Exhibit (b) EX-99-906CERT Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 James E. Ross, President (Principal Executive Officer) and Gary L. French, Treasurer (Principal 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/ James E. Ross --------------------------------- James E. Ross President (Principal Executive Officer) By: /s/ Gary L. French --------------------------------- Gary L. French Treasurer (Principal Financial Officer) Date: August 24, 2006