Reintroduction of an opposition procedure against patents in Japan 

The opposition procedure has been reintroduced in Japan. It will be applied to patents published on and after April 1, 2015.


It will be open to all third parties.


It will be possible to file an opposition within six months of the publication date of the mention of the patent grant.


Opposition may only be filed on grounds of non-compliance with the substantive conditions for patentability (novelty, inventive step, enablement requirement, support requirement, clarity requirement) and not for reasons relating to private business matters (invention theft, for example).


The procedure shall be in writing with no possibility for an oral procedure. It will be possible for the patent holder to amend the patent claims, description and/or designs. The opponent may respond following such amendments.


If the patent is revoked, such revocation will be retroactive.


The patent holder, but not the opponent, may lodge an appeal against the decision. The opponent may, however, initiate invalidation proceedings if all conditions are met.


The invalidation proceedings currently in place will remain unchanged, with the exception that it will only be possible for an interested party to initiate such proceedings whereas anyone may currently do so.


We would be happy to provide you with further information on this subject through our dedicated Japanese Desk and our network of agents in Japan.


Contact: Céline BOURNEUF

  • Publication date: December 2014
  • By : Céline BOURNEUF
    IP ALERT Chemistry - Life Sciences
    IP ALERT Electro - Mecha
  • Subject(s) : Patents
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