A method and apparatus for inspecting a defect of a surface of a sample in which a laser beam is irradiated on a sample surface so that at least a part of an illumination field of the laser beam illuminates a first area of the sample surface, a plurality of scattered light rays from the first area caused by the irradiation in the irradiating is detected, errors of inclination of an illumination apparatus and a sensor for the plurality of scattered light rays detected are corrected, the plurality of scattered light rays corrected is at least one of added and averaged, a defect on the sample surface based on the plurality of scattered light rays in accordance with the correcting of errors of inclination of the illumination apparatus and the sensor is determined.