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 June 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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