Facts
Dr. Stephen Thaler filed an international application under the Patent Cooperation Treaty for an invention relating to a food container and to devices and methods for attracting attention, and entered the Japanese national phase in August 2020. In the field for the inventor’s name he wrote “DABUS, an artificial intelligence that autonomously invented this invention”. The Japan Patent Office ordered him to amend the filing to name a natural person. When he did not, the Commissioner of the Patent Office dismissed the application in October 2021, and an administrative appeal failed in 2022. The Tokyo District Court rejected his action to annul the dismissal in May 2024, and he appealed to the Intellectual Property High Court.
Question
The question was whether Japan’s Patent Act allows a patent to be granted for an invention made by an AI system, and therefore whether the inventor named in an application must be a natural person. Thaler argued that nothing in the Act limits inventors to human beings. He also claimed that, as the owner of DABUS, he should hold the right to obtain the patent, relying on civil-law rules on the ownership of fruits derived from property. The court assessed these arguments in light of the Act as a whole.
Decision
The Intellectual Property High Court dismissed the appeal. Reading the Patent Act as a whole, including Article 29(1), it held that the right to obtain a patent arises only for inventions made by a natural person, and the Act contains no rules on how such a right could arise for, or belong to, anyone else. It followed that AI-made inventions cannot be patented under the current Act, and the requirement to state the inventor’s name presupposes a natural person. The court rejected the civil-law argument. It added that whether and how to protect AI inventions should be addressed through legislation, after broad and careful debate on their impact on society.
Why it matters
The judgment makes clear that, under Japanese law, an AI system cannot be named as inventor and that inventions without a human inventor fall outside the patent system. Like the Tokyo District Court, the High Court pointed to the legislature, which leaves open whether Japan will create a separate regime for AI-generated inventions. The case did not concern inventions made by humans with the help of AI.
Related stages
According to Japanese press reports, the Second Petty Bench of the Supreme Court of Japan decided on March 4, 2026 not to accept Thaler’s final appeal for review (上告不受理), making the judgment final. For AI and authorship under U.S. copyright law, see Thaler v. Perlmutter.