[ASE Technology Holding] Announcement on behalf of subsidiary ASE Semiconductor Manufacturing Co., Ltd. regarding acquisition of factory engineering services from Fantasy System Technology Co., Ltd. for business use

1. Name and Nature of the Target Item (e.g., Land in Section XX, Lot XX, North District, Taichung City): Factory engineering services for business use 2. Date of Fact Occurrence: 115/4/17~115/4/30 3. Board of Directors Approval Date: Not applicable 4. Other Approval Dates: Approval Level: General Manager Approval April 30, 2026 (Republic of China calendar) 5. Transaction Quantity (e.g., XX square meters, equivalent to XX ping), Unit Price, and Total Transaction Amount: Transaction Quantity: One batch Unit Price: NT$526,084,000 (excluding tax) Cumulative Total Transaction Amount: NT$526,084,000 (excluding tax) 6. Transaction Counterparty and Relationship with the Company (If the counterparty is an individual and not a related party, their name may be omitted): Transaction Counterparty: Fantasy System Technology Co., Ltd. Relationship with the Company: None 7. If the counterparty is a related party, also announce the reason for selecting the related party as the transaction object, the previous owner, the relationship between the previous owner, the company, and the transaction counterparty, the date of previous transfer, and the transfer amount: Not applicable 8. If the owner of the transaction target has been a related party of the company within the last five years, also announce the date of acquisition and disposal, price, and relationship with the company at the time of transaction: Not applicable 9. Estimated Disposal Gain (or Loss) (Not applicable for asset acquisition) (Deferred items should be listed to indicate recognition status): Not applicable 10. Delivery or Payment Terms (including payment period and amount), Contractual Restrictions, and Other Important Agreements: Delivery or Payment Terms: Wire transfer or letter of credit payment Contractual Restrictions: None Other Important Agreements: None 11. Method of Decision for this Transaction (e.g., tender, bid, or negotiation), Basis for Price Determination, and Decision-Making Unit: Method of Decision and Basis for Price Determination: Bid and negotiation Decision-Making Unit: Handled according to the company's authority limits 12. Professional Appraisal Firm or Company Name and Appraisal Amount: Not applicable 13. Name of Professional Appraiser: Not applicable 14. Professional Appraiser's Practice Certificate Number: Not applicable 15. Is the appraisal report a limited price, specific price, or special price? No or not applicable 16. Have you not yet obtained the appraisal report? No or not applicable 17. Reason for not obtaining the appraisal report: Not applicable 18. In case of significant differences in appraisal results, the reasons for the differences and the accountant's opinion: Not applicable 19. Name of Accounting Firm: Not applicable 20. Name of Accountant: Not applicable 21. Accountant's Practice Certificate Number: Not applicable 22. Broker and Brokerage Fee: None 23. Specific Purpose or Use of Acquisition or Disposal: For production and business operations 24. Opinions of Directors Expressing Dissent in this Transaction: Not applicable 25. Is this transaction a related party transaction? No 26. Date of Supervisor's Approval or Audit Committee's Consent: Not applicable 27. Did this transaction involve acquiring real estate or its usage rights from a related party? No 28. Price assessed according to Article 16 of the "Regulations Governing the Acquisition or Disposal of Assets by Publicly Offered Companies": Not applicable 29. If the price assessed in the previous paragraph is lower than the transaction price, the price assessed according to Article 17 of the same Regulations: Not applicable 30. Date of previous significant information announcement for the same event: Not applicable 31. Other Matters to Note: None