← 글 목록← All articles

What is the inventive step standard under Article 29(2) of the Korean Patent Act?

Sangwook Je, Partner · Published

Brief summary

  • The standard in Article 29(2) of the Patent Act (특허법) is whether a person skilled in the art could easily have made the invention from inventions that were public before filing. If so, no patent is granted.
  • Prior art counts whether it was disclosed in Korea or abroad. The reference point is the time of filing. If a priority claim under the Treaty is made, the filing date of the first application is the reference point, but only for inventions described in that first application.
  • The Examination Guidelines of the Ministry of Intellectual Property (지식재산처) use a four-step assessment. The main viewpoints are motivation to combine, ordinary creativity, and an advantageous effect.
  • The Supreme Court of Korea prohibits hindsight, that is, an assessment that assumes knowledge gained from reading the specification.

This article is based on the Patent Act in force from 11 November 2025 and the Patent Examination Guidelines (특허·실용신안 심사기준) in force from 13 March 2026. Last verified on 9 October 2026.

Last verified

Article 29(2) at a glance

Item Rule Basis
What is assessed The invention stated in the claim. Each claim is assessed separately Examination Guidelines, Part 3, Chapter 3, 4.
Reference point Before the filing of the patent application. Judged by the time of day, not by the date Patent Act, Art. 29(2); Examination Guidelines 3.1
Application with a priority claim under the Treaty For an invention described in the first application, the filing date of the first application is treated as the Korean filing date Patent Act, Art. 54(1); Examination Guidelines, Part 6, Chapter 3, 5.
PCT international application Deemed a patent application filed on the international filing date Patent Act, Art. 199(1)
Prior art Publicly known inventions, publicly practiced inventions, publications and telecommunication lines, in Korea or abroad Patent Act, Art. 29(1), each subparagraph
Who judges A person with ordinary knowledge in the technical field of the invention Patent Act, Art. 29(2)
Test Whether the invention could easily have been made from the prior art Patent Act, Art. 29(2)
Where it is contested Grounds for rejection in examination, request for revocation of a granted patent, trial for invalidation, defense in an infringement action Patent Act, Arts. 62, 132-2 and 133; Supreme Court Decision 2010Da95390

The statute says only “could easily have been made”

Under Article 29(2) of the Patent Act, no patent is granted for an invention that a person skilled in the art could easily have made from the inventions listed in the subparagraphs of paragraph (1). [1] The term “inventive step” (진보성) does not appear in the statute. The Examination Guidelines explain that an invention meeting this requirement is called an invention “with an inventive step”. [2]

Article 29 was wholly amended on 11 June 2014, and the amended Act entered into force on 1 January 2015. [1] Before the amendment, paragraph (2) used an older Korean expression for “a person with ordinary knowledge could easily make the invention”. [1]

The statement of reasons for the amendment made by Act No. 12753 says that the amendment makes the sentences of the Act easier to understand. Article 29 is not among the five main points listed in that statement. [1] The Supreme Court of Korea described the same method of assessment in a 2009 decision and in a 2016 decision. [3][6]

The amended Patent Act that is scheduled to enter into force on 16 March 2027 (Act No. 21955) has the same text of Article 29 as the current Act. [1]

Prior art is anything disclosed anywhere in the world before the time of filing

The prior art for Article 29(2) is the inventions listed in the subparagraphs of Article 29(1). Subparagraph 1 covers inventions publicly known or publicly practiced in Korea or abroad. Subparagraph 2 covers inventions described in a publication distributed in Korea or abroad, or made available to the public through telecommunication lines. [1]

Article 29(2) refers only to the inventions in the subparagraphs of paragraph (1). An earlier application made public after the filing (Art. 29(3) and (4)) is not included in paragraph (2). Paragraphs (3) and (4) cover the case where the invention is identical to one described in the earlier application. [1]

“Before the filing of the patent application” is judged by the time of day, not by the date. The Examination Guidelines state that this expression takes the hour, minute and second of filing into account. [2] A disclosure made abroad is converted into Korean time and compared with the time of filing. [2]

For an application with a priority claim under the Treaty, the filing date in the country party to the treaty is treated as the Korean filing date when Article 29 is applied (Patent Act, Art. 54(1)). [1] The Examination Guidelines limit this to an invention identical to one described in the first application. For an invention that was not in the first application, the actual Korean filing date is the reference point (Examination Guidelines, Part 6, Chapter 3, 5.). [2]

A PCT international application designating Korea is deemed a patent application filed on the international filing date (Patent Act, Art. 199(1)). [1] The Examination Guidelines treat a priority claim under the PCT as a priority claim under the Treaty (Examination Guidelines, Part 5, Chapter 3, 4.6). [2]

There is an exception for the applicant’s own disclosure. Article 30(1) of the Patent Act protects an application filed within 12 months from the date on which the invention of the person entitled to the patent became public. When Article 29(1) and (2) are applied, that invention is deemed not to have become public. [1] If the person disclosed the invention voluntarily, the written patent application must state this, and the supporting document must be filed within 30 days from the filing date (Art. 30(2)). [1]

This exception has two limits. First, a case where the application was laid open or the registration was published, in Korea or abroad under a treaty or an Act, is excluded from voluntary disclosure (proviso to Art. 30(1), subparagraph 1). [1] Second, the 12 months are counted to the actual Korean filing date, not to the priority date. A priority claim under the Treaty does not move the filing date back when Article 30 is applied (Examination Guidelines, Part 6, Chapter 3, 5.). [2] For a PCT international application, the international filing date is the filing date (Patent Act, Art. 199(1)). [1]

Publicly known and publicly practiced inventions were extended to those abroad by an amendment in force from 3 March 2006. [1] For applications filed before 1 July 2013, telecommunication lines were limited to those specified by Presidential Decree (Addenda to Act No. 11654, Art. 6). [1]

Examiners assess inventive step in four steps

Part 3, Chapter 3 of the Examination Guidelines of the Ministry of Intellectual Property sets out the assessment of inventive step in four steps. [2]

  1. Identify the invention stated in the claim.
  2. Identify the cited inventions. More than one may be identified.
  3. Select the closest cited invention, compare it with the claimed invention and confirm the differences.
  4. Decide whether a person skilled in the art could easily have arrived at the claimed invention despite those differences. This is judged in the light of the other cited inventions, the common general technical knowledge before filing, and empirical rules.

There are three main viewpoints: whether the cited inventions provide a motivation, whether the difference is only an exercise of ordinary creativity, and whether there is an advantageous effect. [2] The Examination Guidelines place the difficulty of the technical configuration at the center and direct the examiner to take into account the distinctiveness of the purpose and the remarkableness of the effect. [2]

The person skilled in the art is not a real person. The Examination Guidelines define this person as a hypothetical person who has the common general technical knowledge before filing and who can obtain everything in the relevant state of the art and make it his or her own knowledge. [2]

In principle, a cited invention is selected from the same technical field, or from a technical field that is reasonably related in problem, effect or use. [2] Inventive step is assessed for each claim. If the independent claim has an inventive step, its dependent claims also have one. If the independent claim lacks an inventive step, the dependent claims are assessed separately. [2]

Motivation and the exercise of ordinary creativity are the grounds for denying inventive step

The Examination Guidelines list four kinds of motivation as strong grounds for finding that an invention could easily have been made: a suggestion in the cited invention, a common problem, a common function or operation, and a related technical field. [2]

If the difference lies only in the exercise of ordinary creativity, inventive step is normally denied unless there is another ground for recognizing it. The Examination Guidelines list six types: selection of a suitable known material, optimization of a numerical range, replacement with equivalents, a simple modification of a design, omission of some elements, and a simple change of use. [2]

Some circumstances work in the other direction. If a prior art document would discourage a person skilled in the art from arriving at the claimed invention, inventive step is not denied on the basis of that document. However, a statement that merely describes the prior art as inferior is not such an obstacle. [2]

Commercial success, praise from the industry, and the fact that nobody worked the invention for a long time are secondary evidence. They do not establish inventive step on their own. [2] Commercial success that results from other factors, such as advertising or sales techniques, is not taken into account. [2] An argument that the invention solved a long-unsolved problem requires objective evidence. [2]

An effect is taken into account only if the specification supports it

An advantageous effect over the cited invention counts in favor of inventive step. Inventive step may be recognized if the effect is different in kind, or is of the same kind but remarkable, and a person skilled in the art could not have predicted it. [2]

However, the effect must have a basis in the specification. Only an effect that is stated in the description of the invention, or that a person skilled in the art can easily recognize from the description and drawings, is taken into account. Any other effect is not taken into account, even if it is proven by experimental results in a written argument. [2]

A combination invention is assessed as a whole, and hindsight is prohibited

It is not permitted to break a claim into its elements and ask only whether each element was known. Supreme Court Decision 2005Hu3284 Decided September 6, 2007 requires an assessment of the difficulty of the whole configuration, in which the elements are organically combined. [4]

When several prior art documents are combined, the question is whether the prior art documents contain a suggestion or motivation that leads to the combination. Even without a suggestion or motivation, inventive step is denied if a person skilled in the art could easily have made the combination. In that case, the state of the art at the time of filing, the common general technical knowledge, the basic problems of the field, the trend of development and the demands of the industry are considered. [4]

There is no limit on the number of prior art references that can be combined. [2] However, the Examination Guidelines direct the examiner to keep in mind that the more cited inventions are combined, the more likely the assessment is hindsight. [2]

Supreme Court Decision 2007Hu3660 Decided November 12, 2009 also set the order of the assessment. First, the scope and content of the prior art, the differences between the invention and the prior art, and the level of skill of the person skilled in the art are established on the evidence. Next, the question is whether the person skilled in the art could easily have made the invention despite those differences. [3] This must not be judged with hindsight on the premise that the technology disclosed in the specification is known. [3] The Supreme Court described the same method again in 2016 (Supreme Court Decision 2014Hu2184 Decided November 25, 2016). [6]

An examiner who finds that a feature is well-known or commonly used art can issue a notice of grounds for rejection without evidence. If the applicant disputes that it is well-known or commonly used art, the examiner must in principle present evidence. [2] If it is difficult to present a document, the examiner can reject the application by giving a sufficient explanation or by pointing out why the applicant’s argument is not appropriate. [2]

Inventive step is still contested after registration

An application that cannot be patented under Article 29 is rejected (Patent Act, Art. 62, subparagraph 1). [1] Before a decision of rejection (decision to reject a patent application), the examiner must issue a notice of grounds for rejection and give the applicant an opportunity to file a written argument (Art. 63(1)). [1] If there are two or more claims, the notice must state specifically which claims are rejected and why (Art. 63(2)). [1]

Proceeding Who When Scope of the inventive step argument Basis
Request for revocation of a granted patent (특허취소신청) Any person From the date of registration of the grant of the patent until six months after the date of publication of registration Only grounds based on inventions in publications and on telecommunication lines. Grounds based on prior art that was in a notice of grounds for rejection and is listed in the Patent Gazette are not allowed Patent Act, Art. 132-2(1) and (2)
Trial for invalidation An interested party or an examiner Possible even after the patent right has been extinguished Any violation of Article 29 Patent Act, Art. 133(1) and (2)
Defense in an infringement action The party against whom the patentee makes a claim During the infringement action Where it is clear that the patent will be invalidated for lack of inventive step Supreme Court Decision 2010Da95390

A request for revocation of a granted patent and a trial for invalidation can each be filed claim by claim. [1]

A request for revocation of a granted patent has two further limits. It applies only to patent rights for which registration of the grant of a patent (registration of establishment of a patent right) was made on or after 1 March 2017 (Addenda to Act No. 14035, Art. 10). [1] It cannot be based on prior art that was in a notice of grounds for rejection and is therefore listed in the Patent Gazette (Art. 132-2(2); Art. 87(3), subparagraph 7). [1]

The court in an infringement action also examines inventive step. The basis is Supreme Court en banc Decision 2010Da95390 Decided January 19, 2012. If it is clear that the patent will be invalidated for lack of inventive step, the defense can be raised even before a trial decision of invalidation becomes final. In that case, a claim for an injunction or for damages is an abuse of rights unless there are special circumstances. [5]

A trial to confirm the scope of a right (권리범위확인심판) is different. The basis is Supreme Court en banc Decision 2012Hu4162 Decided March 20, 2014. In a trial to confirm the scope of a right, the scope of the right must not be denied on the ground that the patent lacks an inventive step. [9]

How Korea differs

The table below sets the statutes and examination guidance of Korea, Europe and the United States side by side. The steps in the examination guidance differ between Korea and Europe.

Jurisdiction Statutory standard Framework in the examination guidance Version
Korea Whether a person skilled in the art could easily have made the invention Four steps. Motivation, ordinary creativity, advantageous effect Examination Guidelines in force from 13 March 2026 [2]
Europe (EPO) Not obvious to a person skilled in the art (Article 56 EPC) Problem-solution approach in three stages: closest prior art, objective technical problem, obviousness Guidelines in force from 1 April 2026 [7]
United States Whether the claimed invention as a whole would have been obvious before the effective filing date (35 U.S.C. 103) The three factual inquiries of the Graham decision, and objective evidence MPEP 2141, R-01.2024 [8]

The Korean Examination Guidelines also start by selecting the “closest cited invention”. [2] The second stage in the EPO Guidelines is to establish the “objective technical problem” from the technical effect of the difference over the closest prior art (G-VII 5.2). [7] The four steps in section 5.1 of the Korean Examination Guidelines have no separate step for formulating a problem. In the Korean Examination Guidelines, the problem appears in places such as the premise for identifying the cited invention (5.1) and the common problem as a ground for motivation (6.1.2). [2]

Supreme Court Decision 2007Hu3660 requires three things to be established: the scope and content of the prior art, the differences between the invention and the prior art, and the level of skill of the person skilled in the art. [3] The factual inquiries of the Graham decision listed in MPEP 2141 are also the scope and content of the prior art, the differences, and the level of ordinary skill. [8]

MPEP 2141 states that the examiner must evaluate objective evidence. Its examples are commercial success, long-felt but unsolved needs, failure of others, and unexpected results. [8] The Korean Examination Guidelines state that commercial success can be referred to as secondary evidence. They state that solving a problem that was unsolved for a long time can be evidence of inventive step. [2]

Registration in another country does not bind Korean examination. The Examination Guidelines state that examination results in other countries are only a reference and do not directly affect the assessment of patentability. [2]

What applicants should do

  • In general, we suggest stating the effect over the prior art, and the basis for it, in the specification as filed. An effect with no basis in the specification is not taken into account even if it is argued in a written argument.
  • When a notice of grounds for rejection for lack of inventive step is received, we suggest contesting whether there is a motivation to combine, together with the differences in configuration. One way is to search the whole of the cited documents for statements that discourage the combination.
  • Where a ground for rejection relies on well-known or commonly used art without evidence, contesting that point in the written argument is worth considering.
  • We suggest submitting registration results from other countries only as reference material, and building separate arguments that fit the viewpoints of the Korean Examination Guidelines.
  • We suggest placing the distinguishing features in separate dependent claims in case the independent claim is rejected. If the independent claim is denied, the dependent claims are assessed separately.
  • If the invention was disclosed before filing, we suggest checking that the Korean filing date, not the priority date, is within 12 months from the date of disclosure.
  • How to respond in an individual case should be confirmed with a Korean agent.

FAQ

Does the Korean Patent Act use the term “inventive step”?

No. Article 29(2) of the Patent Act states only that no patent is granted if the invention could easily have been made. “Inventive step” is the name that the Examination Guidelines and the case law give to this requirement. [1][2]

Is technology disclosed only outside Korea prior art in Korea?

Yes. Article 29(1) of the Patent Act covers publicly known inventions, publicly practiced inventions, publications and telecommunication lines, in Korea or abroad. [1]

Will an effect be recognized if experimental data are filed after a notice of grounds for rejection?

It is taken into account if the effect has a basis in the specification. An effect that is not stated in the description of the invention and cannot be inferred from the description or drawings is not taken into account. [2]

If a patent was granted in the United States or Europe, is inventive step also recognized in Korea?

No. The Examination Guidelines treat examination results in other countries only as a reference. [2]

Is inventive step no longer contested after registration?

It is contested. Inventive step is examined again in a request for revocation of a granted patent, in a trial for invalidation, and in the abuse-of-rights defense in an infringement action. [1][5] In a trial to confirm the scope of a right, the scope of the right cannot be denied on the ground of lack of inventive step. [9]

How DEFINE IP Law Firm handles this

DEFINE IP Law Firm checks inventive step issues first at the stage of drafting the specification, before filing. After a notice of grounds for rejection is received, we check the differences from the cited inventions again, claim by claim. For questions about responding to inventive step rejections of Korean patent applications, please write to contact@defineip.kr.

Sources

  1. Ministry of Intellectual Property (지식재산처), Patent Act (특허법), Act No. 21134, Articles 29, 30, 54, 62, 63, 87, 132-2, 133 and 199, Addenda to Acts No. 11654 and No. 14035, in force from 2025-11-11. Earlier versions (in force from 2005-12-01, 2006-03-03 and 2014-07-01), the statement of reasons for the amendment made by Act No. 12753, and Article 29 of the version scheduled to enter into force (Act No. 21955, in force from 2027-03-16). https://www.law.go.kr/법령/특허법 (verified 2026-10-09)
  2. Ministry of Intellectual Property (지식재산처), Patent Examination Guidelines (특허·실용신안 심사기준), MOIP Established Rule No. 7 (지식재산처예규 제7호), Part 3, Chapter 3 “Inventive Step”; Part 5, Chapter 3, 4.6; Part 6, Chapter 3, 5., in force from 2026-03-13. https://www.law.go.kr/행정규칙/특허·실용신안심사기준 (verified 2026-10-09)
  3. Supreme Court Decision 2007Hu3660 Decided November 12, 2009 (대법원 2009. 11. 12. 선고 2007후3660 판결). https://www.law.go.kr/판례/(2007후3660) (verified 2026-10-09)
  4. Supreme Court Decision 2005Hu3284 Decided September 6, 2007 (대법원 2007. 9. 6. 선고 2005후3284 판결). https://www.law.go.kr/판례/(2005후3284) (verified 2026-10-09)
  5. Supreme Court en banc Decision 2010Da95390 Decided January 19, 2012 (대법원 2012. 1. 19. 선고 2010다95390 전원합의체 판결). https://www.law.go.kr/판례/(2010다95390) (verified 2026-10-09)
  6. Supreme Court Decision 2014Hu2184 Decided November 25, 2016 (대법원 2016. 11. 25. 선고 2014후2184 판결). https://www.law.go.kr/판례/(2014후2184) (verified 2026-10-09)
  7. European Patent Office, European Patent Convention Article 56; Guidelines for Examination in the EPO, Part G, Chapter VII, 5, 5.1, 5.2, 5.3 (April 2026 edition), in force from 2026-04-01. https://www.epo.org/en/legal/guidelines-epc/2026/g_vii_5.html (verified 2026-10-09)
  8. United States Patent and Trademark Office, Manual of Patent Examining Procedure § 2141 [R-01.2024]. https://www.uspto.gov/web/offices/pac/mpep/s2141.html (verified 2026-10-09)
  9. Supreme Court en banc Decision 2012Hu4162 Decided March 20, 2014 (대법원 2014. 3. 20. 선고 2012후4162 전원합의체 판결). https://www.law.go.kr/판례/(2012후4162) (verified 2026-10-09)