<ARTICLE> 5
<LEGEND>
THIS SCHEUDLE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
UNAUDITED CONSOLIDATED FINANCIAL STATEMENT OF ADE CORPORATION FOR THE NINE
MONTHS ENDED JANAURY 31, 1999.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          APR-30-1999
<PERIOD-START>                              MAY-1-1998
<PERIOD-END>                               JAN-31-1999
<CASH>                                          61,628
<SECURITIES>                                         0
<RECEIVABLES>                                   10,838
<ALLOWANCES>                                         0
<INVENTORY>                                     26,057
<CURRENT-ASSETS>                               113,997
<PP&E>                                          24,693
<DEPRECIATION>                                       0
<TOTAL-ASSETS>                                 153,843
<CURRENT-LIABILITIES>                           15,703
<BONDS>                                          8,722
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           132
<OTHER-SE>                                     129,862
<TOTAL-LIABILITY-AND-EQUITY>                   153,843
<SALES>                                         48,699
<TOTAL-REVENUES>                                48,699
<CGS>                                           36,465
<TOTAL-COSTS>                                   36,465
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                             (2,115)
<INCOME-PRETAX>                               (22,792)
<INCOME-TAX>                                   (8,235)
<INCOME-CONTINUING>                           (14,557)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                  (15,311)
<EPS-PRIMARY>                                   (1.18)
<EPS-DILUTED>                                   (1.18)