1934 Act Registration No. 1-14700

SECURITIES AND EXCHANGE COMMISSION

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 OF
THE SECURITIES EXCHANGE ACT OF 1934

For the month of September 2004

Taiwan Semiconductor Manufacturing Company Ltd.

No. 8, Li-Hsin Rd. 6,
Hsinchu Science Park,
Taiwan
(Address of Principal Executive Offices)

     (Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.)

Form 20-F þ                      Form 40-F o

     (Indicate by check mark whether the registrant by furnishing the information contained in this form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.)

Yes o                      No þ

     (If “Yes” is marked, indicated below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82:           .)

TSMC August Sales Set Record High

Hsinchu, Taiwan, September 9, 2004 - Taiwan Semiconductor Manufacturing Company Ltd. (TSMC) (TAIEX: 2330, NYSE: TSM) today said that net sales for August 2004 reached NT$23,414 million, marking the fifth consecutive monthly record. August 2004 sales increased 1.2 percent sequentially and grew yet another 27.8 percent on a year-over-year basis.

Revenues for January through August 2004 totaled NT$168,944 million, an increase of 34.9 percent over the same period in 2003.

# # #

TSMC Spokesperson:
Ms. Lora Ho
Vice President and CFO
Tel: 886-3-566-4602

TSMC Deputy Spokesperson:
Mr. J.H. Tzeng
PR Department Manager
Tel: 886-3-666-5028 (O) / 886-928-882-607(Mobile)
Fax: 886-3-567-0121
E-mail: jhtzeng@tsmc.com

For further information, please contact:
Mr. Richard Chung
PR Principal Specialist
Tel: 886-3-666-5038 (O) / 886-911-258-751(Mobile)
Fax:03-5670121
E-Mail: cychung@tsmc.com

Taiwan Semiconductor Manufacturing Company Limited

This is to report the changes or status of 1) sales volume, 2) funds lent to other parties, 3) endorsements and guarantees, and 4) financial derivative transactions for the period of August 2004.

1) Sales volume (in NT$: thousand)

2) Funds lent to other parties (in NT$: thousand)

3) Endorsements and guarantees (in NT$: thousand)

4) Financial derivative transactions (in thousand)

a-1. Hedging purpose (for assets / liabilities denominated in foreign currencies)

a-2. Hedging purpose (for the position of fixed rate liabilities / floating rate assets)

     b. Trading purpose: None.

SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.