3711 ASE Holding

Disclosure Date: 1150710 Statement Date: 1150709 Statement Time: 171056 Company Code: 3711 Company Name: ASE Holding Subject: Announcement on behalf of subsidiary ASE Semiconductor Manufacturing Co., Ltd. regarding the acquisition of machinery and equipment for business operations from EO Technics Co., Ltd. Compliance Clause: Item 20 Factual Date: 1150709

1. Name and nature of the subject matter (e.g., land located in Section XX, Subsection XX, North District, Taichung City): Machinery and equipment for business operations

2. Factual Date: 114/7/18 ~ 115/7/9

3. Board approval date: Not applicable

4. Other approval dates: Approval level: Approved by General Manager Date: July 9, 115 (2026)

5. Quantity of transaction units (e.g., XX square meters, equivalent to XX ping), unit price, and total transaction amount: Transaction quantity: One batch Unit price: NT$1,023,448 thousand (excluding tax) Cumulative total transaction amount: NT$1,023,448 thousand (excluding tax)

6. Counterparty and its relationship with the company (if the counterparty is an individual and not a related party of the company, name disclosure may be omitted): Counterparty: EO Technics Co., Ltd. Relationship with the company: None

7. If the counterparty is a related party, state the reason for selecting the related party as the transaction party, the previous transferor, the relationship among the previous transferor, the company, and the counterparty, the previous transfer date, and the transfer amount: Not applicable

8. If the owner of the subject matter within the past five years was a related party of the company, disclose the related party's acquisition and disposal date, price, and relationship with the company at the time of transaction: Not applicable

9. Estimated gain (or loss) from disposal (not applicable for asset acquisition) (if deferred, provide a table showing recognition): Not applicable

10. Delivery or payment terms (including payment periods and amounts), contractual restrictions, and other important agreements: Delivery or payment terms: Payment by telegraphic transfer or letter of credit Contractual restrictions: None Other important agreements: None

11. Method of determining the transaction (e.g., bidding, price comparison, or negotiation), basis for price determination, and decision-making unit: Transaction determination method and price basis: Price comparison and negotiation Decision-making unit: In accordance with the company's approval authority regulations

12. Name of professional appraiser firm or company and appraisal amount: Not applicable

13. Name of professional appraiser: Not applicable

14. Professional appraiser license number: Not applicable

15. Whether the appraisal report is for a limited price, specific price, or special price: No or not applicable

16. Whether an appraisal report has not yet been obtained: No or not applicable

17. Reason for not obtaining the appraisal report: Not applicable

18. If there is a significant difference in the appraisal result, explain the reason and provide auditor's opinion: Not applicable

19. Auditor firm name: Not applicable

20. Auditor name: Not applicable

21. Auditor license number: Not applicable

22. Broker and brokerage fees: None

23. Specific purpose or use of the acquisition or disposal: For production and operational use

24. Dissenting director's opinion on this transaction: Not applicable

25. This transaction is a related-party transaction: No

26. Date of supervisor approval or audit committee consent: Not applicable

27. This transaction involves acquiring real estate or right-of-use assets from a related party: No

28. Valuation price under Article 16 of the 'Asset Acquisition and Disposal Rules for Publicly Issued Companies': Not applicable

29. Valuation price under Article 17 of the same rules, if the valuation under the previous item is lower than the transaction price: Not applicable

30. Previous date of material information disclosure regarding the same event: Not applicable

31. Other disclosures: None