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: February 10, 2004		      /s/  Henry C. Pao
				      ____________________________
				      Henry C. Pao, Ph.D.
				      Chief Executive Officer and
				      Chief Financial Officer
				     (Principal Executive and Financial Officer)