Although a patent invalidation action is considered to be a type of public review system, it has the legal nature of a private rights dispute in general. Therefore, the patent invalidation petitioner bears the burden of proof to provide reasons for the patent invalidation request (Article 73(1) of the Patent Act).

With regard to patent invalidation proceedings, certain principles, such as the disposition principle and the issue sorting in the Code of Civil Procedure are also adopted. However, the Patent Act retains some characteristics of the principle of ex officio in patent invalidation proceedings. Article 75 of the Patent Act states that:

"When conducting invalidation proceedings, the Specific Patent Agency may, by ex officio, examine the reason(s) and evidence not provided by the invalidation petitioner but within the scope of the invalidation claims, and notify the patentee to respond within a specific time period. The invalidation proceedings shall be conducted accordingly if the patentee fails to respond within the time period."

However, when and to what extent should the IP Office (IPO) conduct ex officio investigations and take the initiative to explore reasons and evidence not provided by the patent invalidation petitioner? This has been a controversial issue for administrative laws in the patent field.

Supreme Administrative Court

The Supreme Administrative Court expressed its opinion on the application and legal effects of the "examination of the reason(s) and evidence not provided by the invalidation petitioner by ex officio" provided in Article 75 of the Patent Act in its judgment of November 17 2016 (2016/610).

In this judgment, the patentee argued that the combination of evidence used by the IPO and the IP Court differed from the combination of evidence presented by the invalidation petitioner when filing the invalidation action. Specifically, the IPO added the combination of Exhibit 5 and other evidence – which were not asserted by the invalidation petitioner – to negate the validity of the disputed patent, but failed to provide the patentee with an opportunity to respond during the patent invalidation proceedings. Therefore, the patentee claimed that the IPO's original decision should be revoked. The Supreme Administrative Court rejected the patentee's argument.

According to the Supreme Administrative Court, Exhibit 5 was not new evidence, since it had been already submitted by the invalidation petitioner to prove that other claims regarding the disputed patent were unpatentable when the patent invalidation action was filed. As for any adjustment to the presented combinations of evidence, it was a change of the means of attack or defence, which was different from the submission of new evidence. Pursuant to Article 33(1) of the IP Case Adjudication Act, the IP Court reviews any new evidence submitted before the end of the oral debate procedure. Therefore, the IP Court can examine any adjustment to the means of attack or defence concerning existing evidence.

The Supreme Administrative Court also pointed out that disputes arising from the new combination of evidence had already been raised during the appeal administrative proceedings and were listed among issues by the IP Court during the administrative litigation proceedings, and the patentee had already made a complete argument against the new combination of evidence during the litigation proceedings. Further, an administrative court should investigate the fact, by ex officio, not restrained by assertions of the parties involved. Therefore, although the reasons on which the administrative agency made its decision were inadmissible, other reasons it illustrated during the litigation proceedings might still be considered legitimate if they already existed when the original decision was rendered, and therefore neither altered the nature of the decision nor undermined the litigation rights of the parties to present arguments in the litigation proceedings, but contributed to the findings of objective facts and the application of law by the court. The Supreme Administrative Court thereby dismissed the appeal filed by the patentee.


According to the judgment rendered by the Supreme Administrative Court, although Article 75 of the Patent Act states that should the IPO, by ex officio, invalidate a patent based on the combination of evidence not presented by the patent invalidation petitioner, the IPO must fulfil its responsibility to notify the patentee to respond beforehand in order to protect the patentee's right of audience. The result of the IPO's failure to perform this responsibility would not constitute sufficient grounds to have its decision revoked as long as relevant evidence had already been included in the files for the patent invalidation and the patentee had been provided with an opportunity to respond during the administrative remedy proceedings.

For further information on this topic please contact Hsiu-Ru Chien or Shih-I Wu at Lee and Li Attorneys at Law by telephone (+886 2 2715 3300) or email ( or The Lee and Li Attorneys at Law website can be accessed at

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