Exhibit 4(t)


                         Plant Building Lease Agreement

                                                           Date: January 1, 2004
Parties:
     ASE (Chung-Li) Inc. ("Party A")
     ASE Test Inc. ("Party B")

Whereas, Party A desires to lease its Plant Building and parking tower located
at the 5th floor, No. 550-5, Sec.1, Chung-hwa Rd., Fu-hwa Li, Chung-Li City,
Tao-Yuan County to Party B under the following agreement.

1.   The Premises and Rent

(1)  Premises: The Plant Building and the Plant Office are separately located at
     5th floor, No. 550-5 and 1st floor, N0.550, Sec.1, Chung-hwa Rd., Fu-hwa
     Li, Chung-Li City, Tao-Yuan County (building register No. 00225-005 and
     land register No.: 1833-0000, Fu-hsin Section, Chung-Li City), for the area
     of 4,282 square meters, the area of parking tower of 797.03 square meters,
     inclusive of ancillary equipments (collectively; "Leased Floor").


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     (2)  Rent: NT$1,182,453 per month, excluding business taxes.

2.   Term of Lease: ten months from 1 January 2004 to 31 October 2004.

3.   Usage: It is for Party B to establish its Chung-Li Plant Building and for
     the uses within its registered business scope. Party B's Chung-Li Plant
     Building will be applied to be registered to the customs as a bonded
     factory.

4.   Party B shall be responsible for the maintenance of the Plant Building and
     the existing equipments except for the building structure (including inner
     and outer walls, floor and the original water and electricity pipelines),
     which shall be Party A's responsibilities. Party B shall make good of any
     damage to the above and Party A shall bear no responsibilities thereof.

5.   Both parties agree that the rent shall be paid starting from the effective
     date of this Agreement.

6.   Party B shall be the owner of any equipment that Party B subsequently
     installs into the premises. After expiry of the lease term, Party B shall
     remove its belongings and return the Leased Floor, under the then current
     condition, to Party A. Party B, during the term of this Agreement, may not
     engage in any construction altering the structure of the Leased Floor
     unless otherwise agreed by Party A.

7.   During the term of this Agreement, the rent and fees for water and
     electricity utilities shall be paid by Party A and advance to the competent
     authority. Party B shall reimburse Party A for such payment pursuant to the
     consumption volume of electricity according to the meters separately
     installed for each of the parties. For the utilities that cannot be counted
     by separate meters, the amount of the reimbursement shall apply the same
     percentage that is used for metered utilities. As to the expenses of other
     utilities that should be jointly shared but the volume of each user cannot
     be decided, the amount of the reimbursement shall be calculated by the
     proportionate area used by such party. The land tax and building tax shall
     be borne by Party A.


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8.   After the signing of this Agreement, in the event that it is necessary to
     apply with the relevant authorities (such as the municipal government or
     the electricity company) to register the change of user, Party A shall
     promptly provide relevant materials as requested by Party B.

9.   Party A shall issue invoices to Party B for the collection of rent on a
     monthly basis and Party B shall remit the rent of the preceding month to
     the corporate account designated by Party A within ten days after receipt
     of invoice.

10.  Party A warrants that it has the legal ownership of the Leased Floor to be
     leased to Party B and Party B's leasing rights will not be affected by the
     encumbrances created by Party A or any other incidents regarding the Leased
     Floor. In case Party B's leasing rights are so affected, Party A shall be
     liable to indemnify Party B's loss resulting therefrom and pay additional
     amount equal to three times of monthly rent under this Agreement as
     compensation.

11.  Party A is the legal owner of the leased Leased Floor and shall procure
     fire insurance policy for it. Party B shall be solely responsible to
     procure fire insurance policies for its movables and equipment.

12.  Party B shall pay penalties as follows for delay payment of rent:

     (1)  5% of a monthly rent if delay is more than one month but less than two
          months;

     (2)  10% of a monthly rent if delay is more than two months but less than
          three months; and

     (3)  if delay is more than three months, Party A may forfeit the security
          deposit and terminate this Agreement.

13.  The security deposit is in an amount of NT$1,500,000. Party B shall remit
     the security deposit to the corporate account designed by Party A at the
     beginning of the lease term. The security deposit shall be returned to
     Party B without bearing any interests upon expiration of this Agreement.

14.  Party B is entitled to a right of first refusal to lease or acquire the
     Leased


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     Floor upon reasonable terms. Party B may not terminate this Agreement
     unless it gives Party A a three-month prior notice in writing and
     compensates Party A for an amount equal to three times of monthly rent
     under this Agreement. However, Party A shall return the security deposit to
     Party B without bearing any interests. In the event Party A intends to
     early terminate this Agreement, the abovementioned terms and conditions
     shall apply.

15.  In the event Party A intends to terminate this Agreement within ninth month
     after the lease commences, Party A shall indemnify Party B for all
     construction, partitioning and fitout expenses according to their book
     value, in addition to the three-month rent as stipulated above.

16.  Both parties agree that in the event Party B's bonded factory status is
     cancelled, the bonded goods shall continue staying in the warehouse of the
     Plant Building for not less than six months for the customs' operations.
     All the expenses incurred thereof shall be borne by Party B.

17.  This Agreement will be executed in two counterparts and come into effect on
     the date of signing. Each of Party A and Party B will hold one copy. The
     Tao-Yuan District Court will be the court of first instance in the event
     any dispute arises in connection with this Agreement.

18.  In the event that Party B (Party A) fails to perform its obligations under
     this Agreement, Party A (Party B) may terminate this Agreement by written
     notice and Party B (Party A) shall be liable to all losses incurred
     thereof.

Party A: ASE (Chung-Li) Inc. [Company chop]
         Supervisor: Cheng Hung-Ben [Chairman's chop]
         Address:    No. 550, Chung-hwa Rd., Chung-Li City, Tao-Yuan County

Party B: ASE Test Inc. [Company chop]
         Chairman: Jason Chang [Chairman's chop]
         Address:  No.10, West Fifth St., Nantze Export Processing Zone,
                   Kaohsiung


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