[UMC] Information Regarding Participation in Investor Conference

Compliance with Article 4, Paragraph XX: 12 Date of occurrence: June 5, 2026 1. Date of the investor conference: June 5, 2026 2. Time of the investor conference: 09:00 AM 3. Location of the investor conference: W Taipei 4. Key highlights of the investor conference: The company is invited to participate in the investor conference "2026 Taiwan Tech Conference" organized by Citigroup. 5. Other relevant information: None For complete financial and operational information, please visit the investor conference list or the investor conference section on the Market Observation Post System.