To make possible deciding whether or not a memory help analysis is performed when respective function tests are ended without a mask memory by comparing the number of defect cells occurring in the last and this time function tests whenever respective function tests are ended and executing the defect help analysis only when the number of this time defect cells are increased.

A defect cell counter 15 is provided accompanying a defect analytic memory 13, and the number of defect cell pieces stored in the defect analytic memory 13 are counted by the defect cell counter 15 whenever respective function tests are ended. When the number of defect cell pieces coincide with the number of defect cells detected by the last function test, the memory help analysis isn't executed to move to the next function test. Further, when the number of defect cells detected by this time function test are more than the number of defect cells detected by the last function test, it is judged so that the defect cells are detected newly, and the memory help analysis is executed. These control operation are executed by a main controller CP.