Completion of a New Manufacturing Building at the Koriyama Plant

Japan, October 8, 2026 – Tokyo Ohka Kogyo Co., Ltd. (headquarters: Nakahara-ku, Kawasaki City; President and Representative Director: Noriaki Taneichi; hereinafter “the Company”) has completed construction of a new manufacturing building for semiconductor photoresists at its Koriyama Plant (Koriyama City, Fukushima Prefecture).

The Koriyama Plant manufactures a wide range of semiconductor photoresists, including advanced materials such as EUV and ArF photoresists. With the semiconductor market expected to grow over the medium to long term, the Company decided to construct a new manufacturing building at the plant—one of the world’s largest facilities of its kind—to further enhance the quality of its products and expand its supply capacity. Construction began in July 2024, and the newly completed building is scheduled to commence operations in November 2026.

Through the automation and digitalization of its manufacturing lines, the new building will serve as a people-friendly smart factory, pursuing high levels of safety and production efficiency while aiming to manufacture photoresists of the highest quality in the world.

Under its medium-term management plan, “tok Medium-Term Plan 2027,” the TOK Group is working to build a resilient supply chain. Looking ahead to continued growth in the semiconductor market, the Group will continue to consider proactive capital investments to expand its production infrastructure and strengthen its R&D capabilities, with the aim of ensuring a stable supply of high-quality products.

Overview of the New Manufacturing Building at the Koriyama Plant
1.Location：1-23 Machiikedai, Koriyama City, Fukushima Prefecture
2.Building area：4,800m²
3.Construction details：Manufacturing building for semiconductor photoresists
4.Investment amount：Approximately ¥23 billion
5.Completion：October 8, 2026
6.Scheduled start of operations：November 2026