Exhibit 31

		 Certifications Under Rule 13a-14(a)/l5d-14(a)

  I, Henry C. Pao, certify that:

  1. I have reviewed this quarterly report on Form 10-Q of Supertex, Inc., a
California corporation;

  2. Based on my knowledge, this quarterly report does not contain any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this quarterly
report;

  3. Based on my knowledge, the financial statements, and other financial
information included in this quarterly report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

  4. I am responsible for establishing and maintaining disclosure controls and
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and I have:

    (a)	designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under my supervision, to
ensure that material information relating to the registrant, including its
consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this quarterly report is being
prepared;

    (b)	evaluated the effectiveness of the registrant's disclosure controls and
procedures and presented in this report my conclusion about the effectiveness
of the disclosure controls and procedures, as of the end of the period covered
by this report based on such evaluation; and

    (c)	disclosed in this report any change in the registrant's internal
control over financial reporting that occurred during the registrant's most
recent fiscal quarter that has materially affected, or is reasonably likely to
materially affect, the registrant's internal control over financial reporting;
and

  5. I have disclosed, based on my most recent evaluation of internal control
over financial reporting, to the registrant's auditors and the audit committee
of registrant's board of directors (or persons performing the equivalent
function):

    (a)	all significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting which are reasonably
likely to adversely affect the registrant's ability to record, process,
summarize, and report financial data and have identified for the registrant's
auditors any material weaknesses in internal controls; and

    (b)	any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrant's internal control over
financial reporting.


Date: August 12, 2003	  _/s/ Henry C. Pao _________
			   Henry C. Pao, Ph.D.
			   Chief Executive Officer and Chief Financial Officer