A defect inspecting apparatus inspects defects of a sample having a pattern formed on the surface. The defect inspecting apparatus is provided with a stage which has a sample placed thereon and linearly moves and turns; a light source; an illuminating optical system, which selects a discretionary wavelength region from the light source and epi-illuminates the sample surface through a polarizer and an objective lens; a detecting optical system, which obtains a pupil image, by passing through reflection light applied by the illuminating optical system from the surface of the sample through the objective lens and an analyzer which satisfies the cross-nichols conditions with the polarizer; and a detecting section which detects defects of the sample by comparing the obtained pupil image with a previously stored pupil image. Conformity of the pattern on a substrate to be inspected can be judged in a short time.