Patent ID: 7916929

Claim:
A method of inspecting a specimen, comprising: illuminating a specimen, on which plural patterns are formed, with light emitted from a light source; capturing a first image of a first area of the specimen in which patterns are formed; capturing a second image of a second area of the specimen in which patterns which are essentially the same with the patterns formed in the first area, are formed; creating data relating to pixels of the first image and corresponding pixels of the second image, for each pixel; determining two thresholds for each pixel for detecting defects directly in accordance with the first image and the second image; and detecting defects on the specimen by processing said first image and the second image by using said two thresholds for each pixel, wherein the thresholds are determined by using information of brightness of a local region of at least one of the first image and the second image, with the local region including an aimed pixel and peripheral pixels of the aimed pixel.