<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS OF ADE CORPORATION FOR THE SIX MONTHS ENDED OCTOBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> APR-30-2000 <PERIOD-START> MAY-01-1999 <PERIOD-END> OCT-31-1999 <CASH> 39,476 <SECURITIES> 0 <RECEIVABLES> 11,521 <ALLOWANCES> 0 <INVENTORY> 26,855 <CURRENT-ASSETS> 91,080 <PP&E> 29,755 <DEPRECIATION> 0 <TOTAL-ASSETS> 138,319 <CURRENT-LIABILITIES> 17,740 <BONDS> 12,237 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 133 <OTHER-SE> 108,209 <TOTAL-LIABILITY-AND-EQUITY> 138,319 <SALES> 25,987 <TOTAL-REVENUES> 25,987 <CGS> 16,153 <TOTAL-COSTS> 16,153 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> (522) <INCOME-PRETAX> (12,292) <INCOME-TAX> 0 <INCOME-CONTINUING> (12,292) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (13,055) <EPS-BASIC> (0.98) <EPS-DILUTED> (0.98)