ASE Holding Announces Subsidiary SPIL's Acquisition of Facility Engineering Project

1. Type of Contract: Facility Engineering 2. Event Date: 05/27/2026 ~ 06/25/2026 3. Board Approval Date: Not applicable 4. Other Approval Dates: Approval Level: Approved by General Manager Date: June 25, 2026 (Minguo Year 115) 5. Contract Counterparty and Relationship with Company: Peng Yi Co., Ltd. Relationship: None 6. Main Contract Contents (including total amount, estimated investment, contract period, restrictions, and other important terms): Total Amount: NTD 508,007,360 Contract Period: May 27, 2026 (Minguo 115) to June 30, 2027 (Minguo 116) Restrictions and Other Important Terms: None 7. Name of Professional Appraisal Firm or Company and Appraisal Result: Not applicable 8. Name of Real Estate Appraiser: Not applicable 9. License Number of Real Estate Appraiser: Not applicable 10. Specific Purpose of Acquisition: For production and operational use 11. Dissenting Director's Opinion on This Transaction: None 12. Whether This Transaction is a Related-Party Transaction: No 13. Date of Supervisor's Approval or Audit Committee's Consent: Not applicable 14. Whether the Appraisal Report is at a Limited, Specific, or Special Price: No or Not applicable 15. Whether Appraisal Report Has Not Yet Been Obtained: No or Not applicable 16. Reason for Not Yet Obtaining Appraisal Report: Not applicable 17. Reasons for Significant Differences in Appraisal Results and Accountant's Opinion: Not applicable 18. Name of Accounting Firm: Not applicable 19. Name of Accountant: Not applicable 20. Accountant's License Number: Not applicable 21. Previous Date of Material Information Disclosure on the Same Event: Not applicable 22. Other Explanatory Matters: None