PURPOSE: To perform the defect inspection of a pattern by comparison between identical patterns using a compare mask which has the completely same design pattern as the mask to be inspected.
CONSTITUTION: A mark reticle R1 is placed above a projection lens 1. On the mark reticle R1, three marks MX, MY, Mθ to be replicated to an object are provided. Reticle alignment microscopes 2, 3 view the marks RM1, RM2 formed on the mark reticle R1. Right under the projection lens 1, a wafer W is mounted on a two-dimensional moving stage 5 and moved by a driver section 6 in x-and y-directions. A resist layer wherein the image reversal is possible is formed on the wafer W, and the pattern of a mask to be inspected is replicated to plural positions of the wafer W. A comparative mask pattern having the same pattern as the mask to be inspected is placed on the wafer W and replicated. Then, by performing a uniform exposure and a positive development of the resist layer on the wafer, only the defective parts will appear as clear parts of the resist pattern.