|   | 1. | I      have reviewed this annual report on Form 10-K of Supertex, Inc., a      California corporation; |
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|   | 2. | Based      on my knowledge, this annual 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      annual report; |
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|   | 3. | Based      on my knowledge, the financial statements, and other financial information      included in this annual 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 annual      report; |
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|   | 4. | The      Registrant’s other officer and I are responsible for establishing and      maintaining disclosure controls and procedures (as defined in Exchange Act      Rules 13a-15(e) and 15d-15(e)) and internal control over financial      reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f) for      the registrant and have: |
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|   | (a) | designed      such disclosure controls and procedures, or caused such disclosure      controls and procedures to be designed under our 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 annual report is      being prepared; |
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|   | (b) | designed      such internal control over financial reporting, or caused such internal      control over financial reporting to be designed under our supervision, to      provide reasonable assurance regarding the reliability of financial      reporting and the preparation of financial statements for external      purposes in accordance with generally accepted accounting      principles; |
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|   | (c) | evaluated      the effectiveness of the registrant's disclosure controls and procedures      and presented in this report our conclusion about the effectiveness of the      disclosure controls and procedures, as of the end of the period covered by      this annual report based on such evaluation;and |
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|   | (d) | disclosed      in this report any change in the registrant’s internal control over      financial reporting that occurred during the registrant’s fourth fiscal      quarter that has materially affected, or is reasonably likely to      materially affect, the registrant’s internal control over financial      reporting; and |
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|   | 5. | The      Registrant’s other officer and I have disclosed, based on our 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): |
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|   | (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 information;  and |
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|   | (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. |
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| Dated:  June      10, 2010 |   |   | /s/      PHILLIP A. KAGEL                                |
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|                                 |   |   | Phillip      A. Kagel                                    |
|                                 |   |   | Vice      President, Finance and Chief Financial Officer |
|                                 |   |   | (Principal      Financial and AccountingOfficer)         |