PURPOSE: To make processing capacity for inspection several times higher than that in the prior art by disposing plural inspecting lens systems in series in the moving direction of scanning and moving said systems successively in performing inspection.

CONSTITUTION: If an automatic inspecting device for defects of patterns provided with, for example, three pieces of inspecting lens systems is assumed to be used for a photomask 20, the inspecting lens systems are first positioned to coordinates (X, Y)=(1, 1) pattern, (1, 2) pattern, and (1, 3) pattern, and these three patterns are compared and collated, whereby the patterns are inspected. If the three photoelectric signals coincide, all the three patterns are judged to be free from any defective parts. The inspecting lens systems move by one step to the right and when the systems finish inspection up to the right end, the systems shift downward, and move by each one step successively to the left, whereby the patterns are inspected.