Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

I, Terry K. Glenn, President of Florida Municipal Bond Fund of Merrill Lynch
Multi-State Municipal Series Trust (the "Fund"), certify that:

      1.    The N-CSR of the Fund (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 Fund.

Dated: March 17, 2003

                                             /s/ Terry K. Glenn
                                             ----------------------------------
                                             Terry K. Glenn,
                                             President of
                                             Florida Municipal Bond Fund of
                                             Merrill Lynch Multi-State
                                             Municipal Series Trust


Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

I, Donald C. Burke, Chief Financial Officer of Florida Municipal Bond Fund of
Merrill Lynch Multi-State Municipal Series Trust (the "Fund"), certify that:

      1.    The N-CSR of the Fund (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 Fund.

Dated: March 17, 2003

                                             /s/ Donald C. Burke
                                             ----------------------------------
                                             Donald C. Burke,
                                             Chief Financial Officer of
                                             Florida Municipal Bond Fund of
                                             Merrill Lynch Multi-State
                                             Municipal Series Trust