PURPOSE: To improve work efficiency of foreign matter analysis by a scanning electron microscope and raise yield in semiconductor process.

CONSTITUTION: SEM stage 9 and scanning electron beam 5 are controlled in CPU 15 by means of a floppy disk 18 storing foreign matter information from an optical wafer inspection device 19 and thus composition contrast of reflected electrons 10 occurring in a specimen is detected. The detected composition contrast is converted to a digital signal in a digital converter 14, and difference between a bare wafer 17 and a contrast of foreign matter 20 is monitored. And thus, search for foreign matter 20 is made automatically by moving SEM stage 9. A spectrum of a foreign matter X-ray analyzed is collated with information of foreign matter registered in advance, so that composition of foreign matter 120 and its source are identified.