EXHIBIT 32.2

                          CERTIFICATION PURSUANT TO 18
                         U.S.C. SECTION 1350 AS ADOPTED
                         PURSUANT TO SECTION 906 OF THE
                           SARBANES-OXLEY ACT OF 2002

      In  connection  with the Quarterly  Report of Castelle (the  "Company") on
Form  10-Q/A  for the  period  ended  September  30,  2004,  as  filed  with the
Securities and Exchange  Commission on the date hereof (the  "Report"),  I, Paul
Cheng,  Chief Financial Officer of the Company,  certify,  pursuant to 18 U.S.C.
ss. 1350, as adopted pursuant to ss. 906 of the Sarbanes-Oxley Act of 2002, that
to my knowledge:

      (1)   The Report fully complies with the  requirements of Section 13(a) 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 Company.


        /s/ Paul Cheng
Name:   Paul Cheng
Title:  Chief Financial Officer

Date:   May 4, 2005

This  certification  accompanies  this  report  pursuant  to Section  906 of the
Sarbanes-Oxley  Act of 2002 and shall not be deemed to be filed by Castelle  for
purposes of Section 18 of the Securities Exchange Act of 1934. A signed original
of this written statement  required by Section 906 has been provided to Castelle
and will be retained by Castelle and  furnished to the  Securities  and Exchange
Commission or its staff upon request.


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