| UNITED      STATESSECURITIES      AND EXCHANGE COMMISSION                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Washington,      D.C.  20549                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| FORM      10-Q                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| (MARK      ONE)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| (x)    Quarterly      Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of      1934                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| For      the quarterly period ended July 3, 2010                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| or                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| (  )   Transition      Report Pursuant to Section 13 or 15(d) of the Securities and Exchange Act      of 1934    (No Fee Required)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| Commission      File No. 0-12718                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| SUPERTEX,      INC.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| (Exact      name of Registrant as specified in its Charter)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |
| California                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | 94-2328535 |
| (State      or other jurisdiction of incorporation or organization)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | (IRS      Employer Identification #) |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |
| 1235      Bordeaux Drive                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Sunnyvale,      California 94089                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| (Address      of principal executive offices)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Registrant's      Telephone Number, Including Area Code:  (408)      222-8888                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Indicate      by check mark whether the Registrant (1) has filed all reports required to      be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934      during the preceding 12 months (or for such shorter period that the      Registrant was required to file such reports), and (2) has been subject to      such filing requirements for the past 90      days.                                Yes  [ X ]                                                                                 No  [    ] |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |
| Indicate      by check mark whether the registrant has submitted electronically and      posted on its corporate Website, if any, every Interactive Data File      required to be submitted and posted pursuant to Rule 405 of Regulation S-T      (§229.405 of this chapter) during the preceding 12 months (or for shorter      period that the registrant was required to submit and post such      files).                               Yes  [   ]                                       No  [   ]                                                                                                                                                                                               |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Indicate      by check mark whether the registrant is an accelerated filer (as defined      in Rule 12b-2 of the Act). Check one.Large      accelerated filer      [   ]                 Accelerated filer [ X      ]                  Non-accelerated filer      [   ]                  Smaller Reporting Company[  ]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |
| Indicate      by check mark whether the registrant is a shell company (as defined in      Rule 12b-2 of the Act).Yes  [   ]                                                                                No  [      X ]                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| Indicate      the number of shares outstanding of each of the issuer’s classes of common      stock, as of the latest practicable date.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |
| Class                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | Outstanding at August 6,    2010 |
| Common      Stock, no par value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | 12,993,455 |
| Exhibit      index is on Page 33                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Total      number of pages: 34                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |

----

| Table of Contents |                                                                                                  | Page No. |
|-------------------|-------------------------------------------------------------------------------------------------------|----------|
|              | PART      I – FINANCIAL INFORMATION                                                             |     |
| Item      1.      | Financial      Statements (Unaudited)                                                                 |     |
|              | Condensed      Consolidated Statements of Income                                                      | 3        |
|              | Condensed      Consolidated Balance Sheets                                                            | 4        |
|              | Condensed      Consolidated Statements of Cash Flows                                                  | 5        |
|              | Notes      to Condensed Consolidated Financial Statements                                             | 6        |
| Item      2.      | Management’s      Discussion and Analysis of Financial Condition and Results of      Operations | 20       |
| Item      3.      | Quantitative      and Qualitative Disclosures About Market Risk                                       | 31       |
| Item      4.      | Controls      and Procedures                                                                          | 32       |
|              |                                                                                                  |     |
|              | PART      II – OTHER INFORMATION                                                                |     |
| Item      1.      | Legal      Proceedings                                                                                | 32       |
| Item      1A.     | Risk      Factors                                                                                     | 33       |
| Item      2.      | Unregistered      Sales of Equity Securities and Use of Proceeds                                      | 33       |
| Item      3.      | Defaults      Upon Senior Securities                                                                  | 33       |
| Item      4.      | Removed      and Reserved                                                                             | 33       |
| Item      5.      | Other      Information                                                                                | 33       |
| Item      6.      | Exhibits                                                                                              | 33       |
|              |                                                                                                  |     |
| Signature         |                                                                                                  | 34       |

----

|                                          |   | Three      Months Ended |   |
|-----------------------------------------------|--------|-------------------------|--------|
|                                          |   | July      3, 2010       |   |   | June      27, 2009 |   |
| Net      sales                                |   | $                       | 23,155 |   |   | $ | 13,555 |   |
| Cost      of sales                            |   |                    | 9,961  |   |   |   | 6,425 |   |
| Gross      profit                             |   |                    | 13,194 |   |   |   | 7,130 |   |
| Research      and development                 |   |                    | 3,511  |   |   |   | 4,005 |   |
| Selling,      general and administrative      |   |                    | 3,311  |   |   |   | 2,790 |   |
| Total      operating expenses                 |   |                    | 6,822  |   |   |   | 6,795 |   |
| Income      from operations                   |   |                    | 6,372  |   |   |   | 335 |   |
| Interest      income                          |   |                    | 203    |   |   |   | 337 |   |
| Other      (expense) income, net              |   |                    | (292   | ) |   |   | 449 |   |
| Income      before provision for income taxes |   |                    | 6,283  |   |   |   | 1,121 |   |
| Provision      for income taxes               |   |                    | 2,175  |   |   |   | 216 |   |
| Net      income                               |   | $                       | 4,108  |   |   | $ | 905 |   |
|                                          |   |                    |   |   |   |   |   |   |
| Net      income per share                     |   |                    |   |   |   |   |   |   |
| Basic                                         |   | $                       | 0.32   |   |   | $ | 0.07 |   |
| Diluted                                       |   | $                       | 0.32   |   |   | $ | 0.07 |   |
| Shares      used in per share computation:    |   |                    |   |   |   |   |   |   |
| Basic                                         |   |                    | 12,957 |   |   |   | 12,884 |   |
| Diluted                                       |   |                    | 13,037 |   |   |   | 12,965 |   |

----

|                                                                                                                          |   | July      3, 2010 |    |   | April      3, 2010 |   |
|-------------------------------------------------------------------------------------------------------------------------------|--------|-------------------|---------|--------|--------------------|--------|
| ASSETS                                                                                                                        |   |              |    |   |               |   |
| Current      Assets:                                                                                                          |   |              |    |   |               |   |
| Cash      and cash equivalents                                                                                                |   | $                 | 12,917  |   |               | $      | 10,153 |   |
| Short-term      investments                                                                                                   |   |              | 100,842 |   |               |   | 76,860 |   |
| Trade      accounts receivable, net                                                                                           |   |              | 12,245  |   |               |   | 10,786 |   |
| Inventories                                                                                                                   |   |              | 16,534  |   |               |   | 15,450 |   |
| Prepaid      expenses and other current assets                                                                                |   |              | 2,054   |   |               |   | 3,726 |   |
| Prepaid      income taxes                                                                                                     |   |              | 2,462   |   |               |   | 2,456 |   |
| Deferred      income taxes                                                                                                    |   |              | 7,978   |   |               |   | 8,162 |   |
| Total      current assets                                                                                                     |   |              | 155,032 |   |               |   | 127,593 |   |
| Long-term      investments                                                                                                    |   |              | 46,171  |   |               |   | 65,000 |   |
| Property,      plant and equipment, net                                                                                       |   |              | 6,797   |   |               |   | 6,791 |   |
| Other      assets                                                                                                             |   |              | 524     |   |               |   | 580 |   |
| Deferred      income taxes                                                                                                    |   |              | 4,816   |   |               |   | 5,254 |   |
| Total      assets                                                                                                             |   | $                 | 213,340 |   |               | $      | 205,218 |   |
|                                                                                                                          |   |              |    |   |               |   |   |   |
|                                                                                                                          |   |              |    |   |               |   |   |   |
| LIABILITIES      AND SHAREHOLDERS’ EQUITY                                                                               |   |              |    |   |               |   |   |   |
| Current      Liabilities:                                                                                                     |   |              |    |   |               |   |   |   |
| Trade      accounts payable                                                                                                   |   | $                 | 4,827   |   |               | $      | 3,748 |   |
| Accrued      salaries and employee benefits                                                                                   |   |              | 11,117  |   |               |   | 11,430 |   |
| Other      accrued liabilities                                                                                                |   |              | 1,156   |   |               |   | 1,167 |   |
| Deferred      revenue                                                                                                         |   |              | 4,329   |   |               |   | 3,962 |   |
| Income      taxes payable                                                                                                     |   |              | 184     |   |               |   | 15 |   |
| Total      current liabilities                                                                                                |   |              | 21,613  |   |               |   | 20,322 |   |
| Income      taxes payable, noncurrent                                                                                         |   |              | 5,104   |   |               |   | 4,520 |   |
| Total      liabilities                                                                                                        |   |              | 26,717  |   |               |   | 24,842 |   |
|                                                                                                                          |   |              |    |   |               |   |   |   |
| Commitments      and contingencies (Note 9)                                                                                   |   |              |    |   |               |   |   |   |
|                                                                                                                          |   |              |    |   |               |   |   |   |
| Shareholders’      equity:                                                                                              |   |              |    |   |               |   |   |   |
| Preferred      stock, no par value -- 10,000 shares authorized, none      outstanding                                         |   |              | -       |   |               |   | - |   |
| Common      stock, no par value -- 30,000 shares authorized; issued and outstanding      12,982 shares and 12,944 shares |   |              | 65,872  |   |               |   | 64,296 |   |
| Accumulated      other comprehensive loss                                                                                     |   |              | (2,003  | )      |               |   | (2,566 | ) |
| Retained      earnings                                                                                                        |   |              | 122,754 |   |               |   | 118,646 |   |
| Total      shareholders' equity                                                                                               |   |              | 186,623 |   |               |   | 180,376 |   |
| Total      liabilities and shareholders' equity                                                                               |   | $                 | 213,340 |   |               | $      | 205,218 |   |
|                                                                                                                          |   |              |    |   |               |   |   |   |

----

|                                                                                                   |   | Three      Months Ended |    |
|--------------------------------------------------------------------------------------------------------|--------|-------------------------|---------|
|                                                                                                   |   | July      3, 2010       |    |   | June      27, 2009 |   |
| CASH      FLOWS FROM OPERATING ACTIVITIES                                                              |   |                    |    |   |   |   |
| Net      income                                                                                        |   | $                       | 4,108   |   |   | $ | 905 |   |
| Non-cash      adjustments to net income:                                                               |   |                    |    |   |   |   |   |   |
| Depreciation      and amortization                                                                     |   |                    | 565     |   |   |   | 665 |   |
| Provision      for doubtful accounts and sales returns                                                 |   |                    | 96      |   |   |   | 5 |   |
| Provision      for excess and obsolete inventories                                                     |   |                    | 252     |   |   |   | 1,468 |   |
| Deferred      income taxes                                                                             |   |                    | 263     |   |   |   | (20 | ) |
| Stock-based      compensation                                                                          |   |                    | 759     |   |   |   | 820 |   |
| Tax      benefit related to stock-based compensation plans                                             |   |                    | 20      |   |   |   | 20 |   |
| Excess      tax benefit related to stock-based compensation                                            |   |                    | (3      | ) |   |   | (4 | ) |
| Unrealized      loss (gain) from short-term investments, categorized as      trading                   |   |                    | 323     |   |   |   | (455 | ) |
| Loss      on disposal of property, plant and equipment                                                 |   |                    | -       |   |   |   | 4 |   |
| Changes      in operating assets and liabilities:                                                      |   |                    |    |   |   |   |   |   |
| Trade      accounts receivable                                                                         |   |                    | (1,578  | ) |   |   | 593 |   |
| Inventories                                                                                            |   |                    | (1,336  | ) |   |   | (2,413 | ) |
| Prepaid      expenses and other assets                                                                 |   |                    | 1,751   |   |   |   | (273 | ) |
| Prepaid      income taxes                                                                              |   |                    | (6      | ) |   |   |   |   |
| Trade      accounts payable and accrued expenses                                                       |   |                    | 713     |   |   |   | 1,261 |   |
| Deferred      revenue                                                                                  |   |                    | 367     |   |   |   | 138 |   |
| Income      taxes payable                                                                              |   |                    | 753     |   |   |   | (1,243 | ) |
| Net      cash provided by operating activities                                                         |   |                    | 7,047   |   |   |   | 1,471 |   |
| CASH      FLOWS FROM INVESTING ACTIVITIES                                                              |   |                    |    |   |   |   |   |   |
| Purchases      of property, plant and equipment, net                                                   |   |                    | (529    | ) |   |   | (105 | ) |
| Purchases      of investments                                                                          |   |                    | (56,223 | ) |   |   | (14,989 | ) |
| Sales      of investments                                                                              |   |                    | 4,904   |   |   |   | 2,818 |   |
| Maturities      of investments                                                                         |   |                    | 46,765  |   |   |   | 5,550 |   |
| Net      cash used in investing activities                                                             |   |                    | (5,083  | ) |   |   | (6,726 | ) |
| CASH      FLOWS FROM FINANCING ACTIVITIES                                                              |   |                    |    |   |   |   |   |   |
| Proceeds      from exercise of stock options and employee stock purchase      plan                     |   |                    | 797     |   |   |   | 360 |   |
| Excess      tax benefit related to stock-based compensation                                            |   |                    | 3       |   |   |   | 4 |   |
| Net      cash provided by financing activities                                                         |   |                    | 800     |   |   |   | 364 |   |
| NET      INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                              |   |                    | 2,764   |   |   |   | (4,891 | ) |
|                                                                                                   |   |                    |    |   |   |   |   |   |
| CASH      AND CASH EQUIVALENTS:                                                                        |   |                    |    |   |   |   |   |   |
| Beginning      of period                                                                               |   |                    | 10,153  |   |   |   | 24,244 |   |
| End      of period                                                                                     |   | $                       | 12,917  |   |   | $ | 19,353 |   |
|                                                                                                   |   |                    |    |   |   |   |   |   |
| Supplemental      cash flow disclosures:                                                               |   |                    |    |   |   |   |   |   |
| Income      taxes paid, net of refunds                                                                 |   | $                       | 316     |   |   | $ | 1,989 |   |
|                                                                                                   |   |                    |    |   |   |   |   |   |
| Supplemental      disclosure of non-cash activities:                                                   |   |                    |    |   |   |   |   |   |
| Additions      to property, plant and equipment included in accounts payable and accrued      expenses |   | $                       | 42      |   |   | $ | 18 |   |

----

----

----

|                                                                                                    |   | July      3, 2010            |   |
|---------------------------------------------------------------------------------------------------------|--------|------------------------------|--------|
|                                                                                                    |   | Fair      value measurements |   |
| Assets:                                                                                                 |   | Level      1                 |   |   | Level      2 |   |   | Level      3 |   |   | Total |   |
| Money      market funds                                                                                 |   | $                            | -      |   |   | $ | 5,665 |   |   | $ | - |   |   | $ | 5,665 |   |
| Municipal      bonds                                                                                    |   |                         | -      |   |   |   | 91,777 |   |   |   | - |   |   |   | 91,777 |   |
| Equity      mutual funds related to non-qualified deferred compensation plan      (“NQDCP”) |   |                         | 7,215  |   |   |   | - |   |   |   | - |   |   |   | 7,215 |   |
| Short-term      investments in ARS                                                                      |   |                         | -      |   |   |   | 1,850 |   |   |   | - |   |   |   | 1,850 |   |
| Long-term      investments in ARS                                                                       |   |                         | -      |   |   |   | - |   |   |   | 46,171 |   |   |   | 46,171 |   |
| Total      assets at fair value                                                                         |   | $                            | 7,215  |   |   | $ | 99,292 |   |   | $ | 46,171 |   |   | $ | 152,678 |   |
| Liabilities:                                                                                            |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Obligation      related to NQDCP                                                                        |   | $                            | 7,215  |   |   | $ | - |   |   | $ | - |   |   | $ | 7,215 |   |

----

|                                      |   | April      3, 2010           |   |
|-------------------------------------------|--------|------------------------------|--------|
|                                      |   | Fair      value measurements |   |
| Assets:                                   |   | Level      1                 |   |   | Level      2 |   |   | Level      3 |   |   | Total |   |
| Money      market funds                   |   | $                            | -      |   |   | $ | 7,341 |   |   | $ | - |   |   | $ | 7,341 |   |
| Municipal      bonds                      |   |                         | -      |   |   |   | 69,390 |   |   |   | - |   |   |   | 69,390 |   |
| Equity      mutual funds related to NQDCP |   |                         | 7,470  |   |   |   | - |   |   |   | - |   |   |   | 7,470 |   |
| Long-term      investments in ARS         |   |                         | -      |   |   |   | - |   |   |   | 65,000 |   |   |   | 65,000 |   |
| Total      assets at fair value           |   | $                            | 7,470  |   |   | $ | 76,731 |   |   | $ | 65,000 |   |   | $ | 149,201 |   |
|                                      |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Liabilities:                              |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Obligation      related to NQDCP          |   | $                            | 7,470  |   |   | $ | - |   |   | $ | - |   |   | $ | 7,470 |   |

| Fair      value measurements of assets using level 3 inputs             |   | Long-term      investments in ARS |    |
|-------------------------------------------------------------------------|--------|-----------------------------------|---------|
| Beginning      balance at April 3, 2010                                 |   | $                                 | 65,000  |   |
| Redemption      of investments in ARS                                   |   |                              | (17,950 | ) |
| Reclassification      from level 3 to level 2 assets                    |   |                              | (1,850  | ) |
| Unrealized      gain recorded in "Accumulated other comprehensive loss" |   |                              | 971     |   |
| Ending      balance at July 3, 2010                                     |   | $                                 | 46,171  |   |

|                                 |   | July      3, 2010 |   |   | April      3, 2010 |   |
|--------------------------------------|--------|-------------------|--------|--------|--------------------|--------|
| Cash                                 |   | $                 | 7,252  |   |               | $      | 2,812 |   |
| Cash      equivalents:               |   |              |   |   |               |   |   |   |
| Money      market funds              |   |              | 5,665  |   |               |   | 7,341 |   |
| Total      cash and cash equivalents |   | $                 | 12,917 |   |               | $      | 10,153 |   |

----

|                                |   | July      3, 2010 |    |
|-------------------------------------|--------|-------------------|---------|
|                                |   | Amortized         |    |   | Unrealized |   |   | Unrealized |   |   | Carrying |   |
|                                |   | Cost              |    |   | Gain |   |   | Loss |   |   | Value |   |
|                                |   |              |    |   |   |   |   |   |   |   |   |   |
| Short-term      investments:        |   |              |    |   |   |   |   |   |   |   |   |   |
| Trading      securities:            |   | $                 | 7,215   |   |   | $ | - |   |   | $ | - |   |   | $ | 7,215 |   |
| Available-for-sale      securities: |   |              |    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Municipal  bonds          |   |              | 91,829  |   |   |   | - |   |   |   | (52 | ) |   |   | 91,777 |   |
| ARS                                 |   |              | 1,850   |   |   |   | - |   |   |   | - |   |   |   | 1,850 |   |
| Total      short-term investments   |   | $                 | 100,894 |   |   | $ | - |   |   | $ | (52 | ) |   | $ | 100,842 |   |
|                                |   |              |    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Long-term      investments:         |   |              |    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Available-for      sale securities  |   | $                 | 49,400  |   |   | $ | - |   |   | $ | (3,229 | ) |   | $ | 46,171 |   |

|                                |   | April      3, 2010 |   |
|-------------------------------------|--------|--------------------|--------|
|                                |   | Amortized          |   |   | Unrealized |   |   | Unrealized |   |   | Carrying |   |
|                                |   | Cost               |   |   | Gain |   |   | Loss |   |   | Value |   |
|                                |   |               |   |   |   |   |   |   |   |   |   |   |
| Short-term      investments:        |   |               |   |   |   |   |   |   |   |   |   |   |
| Trading      securities:            |   | $                  | 7,470  |   |   | $ | - |   |   | $ | - |   |   | $ | 7,470 |   |
| Available-for-sale      securities: |   |               |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Municipal  bonds          |   |               | 69,393 |   |   |   | - |   |   |   | (3 | ) |   |   | 69,390 |   |
| Total      short-term investments   |   | $                  | 76,863 |   |   | $ | - |   |   | $ | (3 | ) |   | $ | 76,860 |   |
|                                |   |               |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Long-term      investments:         |   |               |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Available-for      sale securities  |   | $                  | 69,200 |   |   | $ | - |   |   | $ | (4,200 | ) |   | $ | 65,000 |   |

|                                                  |   | July      3, 2010 |    |   | April      3, 2010 |   |
|-------------------------------------------------------|--------|-------------------|---------|--------|--------------------|--------|
| Short-term      investments:                          |   |              |    |   |               |   |
| Trading      securities:                              |   |              |    |   |               |   |
| Due      in one year or less                          |   | $                 | 7,215   |   |               | $      | 7,470 |   |
| Available-for-sale      securities:                   |   |              |    |   |               |   |   |   |
| Due      in one year or less                          |   |              | 91,777  |   |               |   | 69,390 |   |
| Due      after ten years                              |   |              | 1,850   |   |               |   | - |   |
| Total      short-term investments                     |   | $                 | 100,842 |   |               | $      | 76,860 |   |
| Long-term      investments:                           |   |              |    |   |               |   |   |   |
| Available-for-sale      securities at amortized cost: |   |              |    |   |               |   |   |   |
| Due      after ten years                              |   | $                 | 46,171  |   |               | $      | 65,000 |   |
| Total      long-term investments                      |   | $                 | 46,171  |   |               | $      | 65,000 |   |

----

| ·   | the      decline in market value is due to unusual general market      conditions; |
|--------------------|------------------------------------------------------------------------------------|

| ·   | these      investments are of high credit quality and a significant portion of them      are collateralized and are guaranteed by the US Department of      Education; |
|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | there      have been no defaults on the ARS held by the Company as of July 3,      2010; |
|--------------------|------------------------------------------------------------------------------------------|

| ·   | their      AAA or Aaa credit ratings have not been reduced as of July 3,      2010; |
|--------------------|-------------------------------------------------------------------------------------|

| ·   | the      Company has no intention to sell the securities below par value and it is      more likely than not that the Company will not be required to sell the      securities until their value returns to par;and |
|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | the      Company received ARS redemptions at par value of $12,150,000 and      $19,250,000, respectively, in fiscal years 2009      and 2010. Additionally, during the three months ended July 3, 2010, the      Company received redemptions at par value totaling $17,950,000. Subsequent      to July 3, 2010, the Company received an additional payment of $1,850,000      for partial redemption at par value of one ARS holding. This amount was      reclassified to short term investments as of July 3,  2010. |
|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

|                                                   |   | July      3, 2010 |   |   | April      3, 2010 |   |
|--------------------------------------------------------|--------|-------------------|--------|--------|--------------------|--------|
| Raw      materials                                     |   | $                 | 1,293  |   |               | $      | 1,221 |   |
| Work-in-process                                        |   |              | 10,512 |   |               |   | 9,978 |   |
| Finished      goods                                    |   |              | 2,112  |   |               |   | 2,229 |   |
| Finished      goods at distributors and on consignment |   |              | 2,617  |   |               |   | 2,022 |   |
| Total      Inventories                                 |   | $                 | 16,534 |   |               | $      | 15,450 |   |

|                                                               |   | July      3, 2010 |   |   | June      27, 2009 |   |
|--------------------------------------------------------------------|--------|-------------------|--------|--------|--------------------|--------|
| Net      income                                                    |   | $                 | 4,108  |   |               | $      | 905 |   |
| Unrealized      gain on available-for-sale investments, net of tax |   |              | 563    |   |               |   | 2,267 |   |
| Comprehensive      income                                          |   | $                 | 4,671  |   |               | $      | 3,172 |   |

----

|                        |   |                     |      |   | Options      Outstanding |   |
|-----------------------------|--------|--------------------------|-----------|--------|--------------------------|--------|
|                        |   | Available      for Grant |      |   | Number      of Shares    |   |   | Weighted      Average Exercise Price |   |
| Balance,      April 3, 2010 |   |                     | 1,117,289 |   |                     |   | 1,444,942 |   |   | $ | 27.31 |   |
| Granted                     |   |                     | (78,440   | )      |                     |   | 78,440 |   |   |   | 27.23 |   |
| Exercised                   |   |                     | -         |   |                     |   | (34,760 | ) |   |   | 20.25 |   |
| Canceled                    |   |                     | 41,400    |   |                     |   | (41,400 | ) |   |   | 26.28 |   |
| Balance,      July 3, 2010  |   |                     | 1,080,249 |   |                     |   | 1,447,222 |   |   | $ | 27.51 |   |

----

|                          |   |                    |   | Options      Outstanding                                 |   | Options      Exercisable             |
|-------------------------------|--------|-------------------------|--------|----------------------------------------------------------|--------|--------------------------------------|
| Range      of Exercise Prices |   | Number      Outstanding |   | Weighted-Average      Remaining Contractual Life (Years) |   | Weighted-Average      Exercise Price |   | Number      Outstanding |   | Weighted-Average      Exercise Price |
|  $15.67                  | -      | $19.99                  |   | 188,920                                                  |   | 0.95                                 |   |        $      17.26 |   | 188,920 |   |        $      17.26 |
|   20.00             | -      | 24.99                   |   | 406,622                                                  |   | 8.40                                 |   |          21.03 |   | 85,742 |   |           20.90 |
|    25.00       | -      | 29.99                   |   | 328,520                                                  |   | 8.29                                 |   |          27.00 |   | 84,100 |   |           26.81 |
|   30.00             | -      | 34.99                   |   | 259,960                                                  |   | 4.30                                 |   |          33.77 |   | 168,605 |   |           33.73 |
|   35.00             | -      | 39.99                   |   | 103,300                                                  |   | 6.98                                 |   |          35.84 |   | 45,320 |   |           35.83 |
|    40.00       | -      | 44.99                   |   | 141,900                                                  |   | 3.33                                 |   |          40.90 |   | 97,100 |   |           40.87 |
|   45.00             | -      | 46.92                   |   | 18,000                                                   |   | 3.41                                 |   |          46.92 |   | 10,800 |   |          46.92 |
|  $15.67                  | -      | $46.92                  |   | 1,447,222                                                |   | 6.01                                 |   |      $      27.51 |   | 680,587 |   |     $      28.06 |

----

|                                                       |   | Three      Months Ended |   |
|------------------------------------------------------------|--------|-------------------------|--------|
|                                                       |   | July      3, 2010       |   |   | June      27, 2009 |   |
| BASIC:                                                     |   |                    |   |   |   |   |
| Net      income                                            |   | $                       | 4,108  |   |   | $ | 905 |   |
| Weighted      average shares outstanding for the period    |   |                    | 12,957 |   |   |   | 12,884 |   |
| Net      income per share                                  |   | $                       | 0.32   |   |   | $ | 0.07 |   |
|                                                       |   |                    |   |   |   |   |   |   |
| DILUTED:                                                   |   |                    |   |   |   |   |   |   |
| Net      income                                            |   | $                       | 4,108  |   |   | $ | 905 |   |
| Weighted      average shares outstanding for the period    |   |                    | 12,957 |   |   |   | 12,884 |   |
| Effect      of dilutive securities: stock options and ESPP |   |                    | 80     |   |   |   | 81 |   |
| Total                                                      |   |                    | 13,037 |   |   |   | 12,965 |   |
| Net      income per share                                  |   | $                       | 0.32   |   |   | $ | 0.07 |   |

----

----

| Description                           |   | Balance      at Beginning of Period |   |   | Charge(1) |   |   | Deductions      and Other(2) |   |   | Balance      at End of Period |   |
|---------------------------------------|--------|-------------------------------------|--------|--------|-----------|--------|--------|------------------------------|--------|--------|-------------------------------|--------|
| Three      months ended July 3, 2010  |   | $                                   | 217    |   |      | $      | 136    |                         |   | $      | (26                           | )      |   | $ | 327 |   |
| Three      months ended June 27, 2009 |   | $                                   | 266    |   |      | $      | 25     |                         |   | $      | (78                           | )      |   | $ | 213 |   |

| Payment      Due by Year |   | Operating      Lease |   |
|--------------------------|--------|----------------------|--------|
| Less      than 1 year    |   | $                    | 1,120  |   |
| 2      years             |   |                 | 746    |   |
| 3      years             |   |                 | 654    |   |
| 4      years             |   |                 | 604    |   |
| 5      years             |   |                 | 604    |   |
| After      5 years       |   |                 | 504    |   |
|                     |   | $                    | 4,232  |   |

----

|                        |   | Three      Months Ended |   |
|-----------------------------|--------|-------------------------|--------|
| Net      Sales              |   | July      3, 2010       |   |   | June      27, 2009 |   |
| Asia      (excluding China) |   | $                       | 6,888  |   |   | $ | 3,085 |   |
| China                       |   |                    | 6,633  |   |   |   | 4,095 |   |
| United      States          |   |                    | 6,597  |   |   |   | 5,133 |   |
| Europe                      |   |                    | 2,830  |   |   |   | 1,177 |   |
| Other                       |   |                    | 207    |   |   |   | 65 |   |
| Net      Sales              |   | $                       | 23,155 |   |   | $ | 13,555 |   |

|                                                |   | July      3, 2010 |   |   | April      3, 2010 |   |
|-----------------------------------------------------|--------|-------------------|--------|--------|--------------------|--------|
| United      States                                  |   | $                 | 5,467  |   |               | $      | 5,630 |   |
| Hong      Kong                                      |   |              | 1,330  |   |               |   | 1,161 |   |
|   Property,      plant and equipment, net |   | $                 | 6,797  |   |               | $      | 6,791 |   |

----

----

----

----

|                     |   | Three      Months Ended |   |
|--------------------------|--------|-------------------------|--------|
| Net      Sales           |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |   | Sequential      Change |   |   | Year-Over-Year      Change |   |
| Medical      Electronics |   | $                       | 8,657  |   |   | $ | 8,214 |   |   | $ | 5,381 |   |   |   | 5 | % |   |   | 61 | % |
| LED      Lighting        |   |                    | 4,421  |   |   |   | 3,664 |   |   |   | 2,876 |   |   |   | 21 | % |   |   | 54 | % |
| Imaging                  |   |                    | 4,602  |   |   |   | 4,055 |   |   |   | 2,638 |   |   |   | 13 | % |   |   | 74 | % |
| Industrial/Other         |   |                    | 3,264  |   |   |   | 2,871 |   |   |   | 1,640 |   |   |   | 14 | % |   |   | 99 | % |
| Telecom                  |   |                    | 2,211  |   |   |   | 1,755 |   |   |   | 1,020 |   |   |   | 26 | % |   |   | 117 | % |
| Net      Sales           |   | $                       | 23,155 |   |   | $ | 20,559 |   |   | $ | 13,555 |   |   |   | 13 | % |   |   | 71 | % |

|                     |   | Three      Months Ended |   |
|--------------------------|--------|-------------------------|--------|
| Net      Sales           |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |
| Medical      Electronics |   |                    | 37     | % |   |   | 40 | % |   |   | 40 | % |
| LED      Lighting        |   |                    | 19     | % |   |   | 18 | % |   |   | 21 | % |
| Imaging                  |   |                    | 20     | % |   |   | 20 | % |   |   | 19 | % |
| Industrial/Other         |   |                    | 14     | % |   |   | 14 | % |   |   | 12 | % |
| Telecom                  |   |                    | 10     | % |   |   | 8 | % |   |   | 8 | % |
| Net      Sales           |   |                    | 100    | % |   |   | 100 | % |   |   | 100 | % |

----

|                        |   | Three      Months Ended |   |
|-----------------------------|--------|-------------------------|--------|
| Net      Sales              |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |   | Sequential      Change |   |   | Year-Over-Year      Change |   |
| Asia      (excluding China) |   | $                       | 6,888  |   |   | $ | 5,757 |   |   | $ | 3,085 |   |   |   | 20 | % |   |   | 123 | % |
| China                       |   |                    | 6,633  |   |   |   | 5,833 |   |   |   | 4,095 |   |   |   | 14 | % |   |   | 62 | % |
| United      States          |   |                    | 6,597  |   |   |   | 6,146 |   |   |   | 5,133 |   |   |   | 7 | % |   |   | 29 | % |
| Europe                      |   |                    | 2,830  |   |   |   | 2,694 |   |   |   | 1,177 |   |   |   | 5 | % |   |   | 140 | % |
| Other                       |   |                    | 207    |   |   |   | 129 |   |   |   | 65 |   |   |   | 60 | % |   |   | 218 | % |
| Net      Sales              |   | $                       | 23,155 |   |   | $ | 20,559 |   |   | $ | 13,555 |   |   |   | 13 | % |   |   | 71 | % |
|                        |   |                    |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| International      Sales    |   | $                       | 16,558 |   |   | $ | 14,413 |   |   | $ | 8,422 |   |   |   | 15 | % |   |   | 97 | % |
| Domestic      Sales         |   |                    | 6,597  |   |   |   | 6,146 |   |   |   | 5,133 |   |   |   | 7 | % |   |   | 29 | % |
| Net      Sales              |   | $                       | 23,155 |   |   | $ | 20,559 |   |   | $ | 13,555 |   |   |   | 13 | % |   |   | 71 | % |

----

|                                                                               |   | Three      Months Ended |   |
|------------------------------------------------------------------------------------|--------|-------------------------|--------|
| (Dollars      in thousands)                                                        |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |
| Gross      Margin Percentage                                                       |   |                    | 57     | % |   |   | 46 | % |   |   | 53 | % |
|                                                                               |   |                    |   |   |   |   |   |   |   |   |   |   |
| Included      in Gross Margin Percentage Above:                                    |   |                    |   |   |   |   |   |   |   |   |   |   |
| Gross      Margin Benefit from Cost of Previously Written Down Inventory      Sold |   | $                       | 329    |   |   | $ | 561 |   |   | $ | 287 |   |
| Percentage      of Net Sales                                                       |   |                    | 1      | % |   |   | 3 | % |   |   | 2 | % |

----

|                         |   | Three      Months Ended |   |
|------------------------------|--------|-------------------------|--------|
| (Dollars      in thousands)  |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |   | Sequential      Change |   |   | Year-Over-Year      Change |   |
| R&D      Expenses        |   | $                       | 3,511  |   |   | $ | 4,038 |   |   | $ | 4,005 |   |   |   | -13 | % |   |   | -12 | % |
| Percentage      of Net Sales |   |                    | 15     | % |   |   | 20 | % |   |   | 30 | % |   |   |   |   |   |   |   |   |

|                         |   | Three      Months Ended |   |
|------------------------------|--------|-------------------------|--------|
| (Dollars      in thousands)  |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |   | Sequential      Change |   |   | Year-Over-Year      Change |   |
| SG&A      Expenses       |   | $                       | 3,311  |   |   | $ | 3,709 |   |   | $ | 2,790 |   |   |   | -11 | % |   |   | 19 | % |
| Percentage      of Net Sales |   |                    | 14     | % |   |   | 18 | % |   |   | 21 | % |   |   |   |   |   |   |   |   |

----

|                                                       |   | Three      Months Ended |   |
|------------------------------------------------------------|--------|-------------------------|--------|
| (Dollars      in thousands)                                |   | July      3, 2010       |   |   | April      3, 2010 |   |   | June      27, 2009 |   |   | Sequential      Change |   |   | Year-Over-Year      Change |   |
| Interest      Income                                       |   | $                       | 203    |   |   | $ | 220 |   |   | $ | 337 |   |   |   | -8 | % |   |   | -40 | % |
| Other      (Expense) Income, Net                           |   |                    | (292   | ) |   |   | 254 |   |   |   | 449 |   |   |   | -215 | % |   |   | -165 | % |
| Total      Interest Income and Other (Expense) Income, Net |   | $                       | (89    | ) |   | $ | 474 |   |   | $ | 786 |   |   |   | -119 | % |   |   | -111 | % |
| Percentage      of Net Sales                               |   |                    | -0     | % |   |   | 2 | % |   |   | 6 | % |   |   |   |   |   |   |   |   |

----

|                                                            |   | Three      Months Ended |   |
|-----------------------------------------------------------------|--------|-------------------------|--------|
|                                                            |   | July      3, 2010       |   |   | June      27, 2009 |   |
| Net      cash provided by operating activities                  |   | $                       | 7,047  |   |   | $ | 1,471 |   |
| Net      cash used in investing activities                      |   |                    | (5,083 | ) |   |   | (6,726 | ) |
| Net      cash provided by financing activities                  |   |                    | 800    |   |   |   | 364 |   |
| Net      increase (decrease)  in cash and cash equivalents |   | $                       | 2,764  |   |   | $ | (4,891 | ) |

----

| ·   | the      decline in market value is due to unusual general market      conditions; |
|--------------------|------------------------------------------------------------------------------------|

| ·   | these      investments are of high credit quality and a significant portion of them      are collateralized and are guaranteed by the U.S. Department of      Education; |
|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | there      have been no defaults on the ARS we held as of July 3,    2010; |
|--------------------|----------------------------------------------------------------------------|

| ·   | their      AAA or Aaa credit ratings have not been reduced as of July 3,      2010; |
|--------------------|-------------------------------------------------------------------------------------|

| ·   | we      have no intention to sell the securities below par value and it is more      likely than not that we will not be required to sell the securities until      their value returns to par; and |
|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | we      received ARS redemptions at par value of $12,150,000 and $19,250,000,      respectively, in fiscal years 2009      and 2010. Additionally, during the three months ended July 3, 2010, the      Company received redemptions at par value totaling $17,950,000. Subsequent      to July 3, 2010, the Company received an additional payment of $1,850,000      for partial redemption at par value of one ARS holding. This amount was      reclassified to short term investments as of July 3,  2010. |
|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

|                                    |   | Payment      Due by Year |   |
|-----------------------------------------|--------|--------------------------|--------|
| Contractual      Obligations            |   | Total                    |   |   | Less      than 1 Year |   |   | 1-2      Years |   |   | 2-3      Years |   |   | 3-4      Years |   |   | 4-5      Years |   |   | After      5 years |   |
| Operating      lease obligations (1)    |   | $                        | 4,232  |   |   | $ | 1,120 |   |   | $ | 746 |   |   | $ | 654 |   |   | $ | 604 |   |   | $ | 604 |   |   | $ | 504 |   |
| Purchase      obligations               |   |                     | 9,491  |   |   |   | 8,773 |   |   |   | 705 |   |   |   | 11 |   |   |   | 2 |   |   |   | - |   |   |   | - |   |
| Total      contractual cash obligations |   | $                        | 13,723 |   |   | $ | 9,893 |   |   | $ | 1,451 |   |   | $ | 665 |   |   | $ | 606 |   |   | $ | 604 |   |   | $ | 504 |   |

|   | (1)      We lease facilities under non-cancelable lease agreements expiring at      various times through April 2016.  Rental expense net of      sublease income for the three months ended July 3, 2010 amounted to      $301,000 compared to $277,000 for the same period of the prior fiscal      year. |
|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

----

----

----

|   | Exhibit      31.1 & 31.2 - Certification of Chief Executive Officer and of Chief      Financial Officer pursuant to Securities and Exchange Act Rules 13a-14(a)      and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley      Act of 2002. |
|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | Exhibit      32.1 & 32.2 - Certification of Chief Executive Officer and of Chief      Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant      to Section 906 of the Sarbanes-Oxley Act of  2002. |
|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   |   |
|--------|--------|

----

|                                  |   |   | SUPERTEX,      INC.                                      |
|---------------------------------------|--------|--------|----------------------------------------------------------|
|                                  |   |   | (Registrant)                                             |
|                                  |   |   |                                                     |
|                                  |   |   |                                                     |
| Dated:  August      9, 2010 |   |   |                                                     |
|                                  |   | By:    | /s/PHILLIP A. KAGEL                                      |
|                                  |   |   | Phillip      A. Kagel                                    |
|                                  |   |   | Vice      President, Finance and Chief Financial Officer |
|                                  |   |   | (Principal      Financial and Accounting Officer)        |

----