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: November 7, 2003

				/s/ Henry C. Pao
				---------------------------
				Henry C. Pao, Ph.D.
				Chief Executive Officer and
				Chief Financial Officer
				(Principal Executive and Financial Officer)