Exhibit (b)

EX-99-906CERT

Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Donald A. Gignac, Chief Executive Officer and Karen D. Gillogly, Chief Financial
Officer of the State Street Master Funds (the "Trust"), certify that:

1.    This Form N-CSR filing for the Trust (the "Report") fully complies with
      the requirements of Section 13(a) or 15(d) of the Securities Exchange Act
      of 1934; and

2.    The information contained in the Report fairly presents, in all material
      respects, the financial condition and results of operations of the Trust.


By:      /s/ Donald A. Gignac
         --------------------
         Donald A. Gignac
         Chief Executive Officer of the Trust

Date:    September 7, 2004


By:      /s/ Karen D. Gillogly
         ---------------------
         Karen D. Gillogly
         Chief Financial Officer of the Trust

Date:    September 7, 2004