PHOTOMASK Announces New Audit Committee Members

1. Date of Change: 2026/06/18 2. Name of Functional Committee: Audit Committee 3. Former Members: Wang Wei-Chen, Independent Director Cheng Huan-Kuei, Independent Director Chan Hui-Fen, Independent Director 4. Former Members' Resumes: Wang Wei-Chen, Independent Director, PHOTOMASK Corporation Cheng Huan-Kuei, Independent Director, PHOTOMASK Corporation Chan Hui-Fen, Independent Director, PHOTOMASK Corporation 5. New Members: Wang Wei-Chen, Independent Director Yang Fang-Xiang, Independent Director Peng Ying-Hui, Independent Director 6. New Members' Resumes: Wang Wei-Chen, Independent Director, PHOTOMASK Corporation Yang Fang-Xiang, Independent Director, Professor (Retired), Department of Chemical and Materials Engineering, Tunghai University Peng Ying-Hui, Independent Director, General Manager, Grandview Private Equity Corporation 7. Nature of Change: Term Expiration 8. Reason for Change: Full renewal due to term expiration 9. Previous Term: 2023/05/24 ~ 2026/05/23 10. Effective Date of New Appointment: 2026/06/18 11. Other Matters to be Disclosed: None Keyword: Material Information