Patent ID: 7692780

Claim:
A surface inspecting apparatus comprising: illumination means for illuminating a repetitive pattern formed in a surface of a specimen with linearly polarized light; setting means for setting an angle at a predetermined value except for zero, the angle being formed between a direction in the surface of an incident plane of the linearly polarized light and a repetitive direction of the repetitive pattern; extraction means for extracting a polarization component perpendicular to a vibration plane of the linearly polarized light from light generated in a specular reflection direction from the repetitive pattern; light acceptance means for accepting the light extracted by the extraction means and supplying light intensity of the specular reflection light; and detection means for detecting a defect of the repetitive pattern based on the light intensity of the specular reflection light supplied from the light acceptance means, wherein the setting means sets the angle formed between the direction in the surface of the incident plane of the linearly polarized light and the repetitive direction of the repetitive pattern such that a contrast becomes maximum, the contrast is an absolute value (1−[(luminance value of image reflected from defective pattern (measured value))/(luminance value of image reflected from normal pattern (measured value))]).