[Amended] Supply contract signed (voluntary)

What happened

Shinsung E&G / Execution of a single sales/supply contract (voluntary disclosure) / (2026.07.31) Execution of a single sales/supply contract (voluntary disclosure)

Amendment report Amendment date: 2026-07-31

1. Disclosure document being amended: Execution of a single sales/supply contract 2. Date the original disclosure document was filed: 2026-05-07 3. Reason for amendment: Change of contract period 4. Amended items: Item / Before amendment / After amendment 5. Contract period -- end date: Before amendment: 2026-07-31; After amendment: -

8. Other matters for reference in investment decisions Before amendment: The "2. Contract details -- contract amount (KRW)" above excludes value-added tax. The "2. Contract details -- recent revenue (KRW)" above is based on the consolidated financial statements for fiscal year 2025. The above construction period and contract amount may change as construction progresses. After amendment: The "2. Contract details -- contract amount (KRW)" above excludes value-added tax. The "2. Contract details -- recent revenue (KRW)" above is based on the consolidated financial statements for fiscal year 2025. The above construction period and contract amount may change as construction progresses. As of 2026.07.31, the Company continues to perform the work, and is pursuing an extension contract for continued performance of the work.

Execution of a single sales/supply contract (voluntary disclosure)

1. Category of sales/supply contract: Construction order received Details: SEMCNS Co., Ltd. clean room expansion construction

2. Contract details Contract amount (KRW): 5,070,000,000 Recent revenue (KRW): 567,454,391,304 Ratio to revenue (%): 0.89 Whether a large corporation: Not applicable

3. Counterparty: SEMCNS Co., Ltd. (SEMCNS Co., Ltd.); Relationship with the Company: -

4. Sales/supply region: Cheongju-si, Chungcheongbuk-do

5. Contract period: Start date 2026-05-07; End date -

6. Main contract terms: Whether there is a down payment/advance payment: Yes; Payment terms, etc.: Advance payment 10%; Progress payment 70%; Completion payment 20%

7. Contract (order) date: 2026-05-07

8. Other matters for reference in investment decisions The "2. Contract details -- contract amount (KRW)" above excludes value-added tax. The "2. Contract details -- recent revenue (KRW)" above is based on the consolidated financial statements for fiscal year 2025. The above construction period and contract amount may change as construction progresses. As of 2026.07.31, the Company continues to perform the work, and is pursuing an extension contract for continued performance of the work.

Related disclosures: -