An apparatus for detecting defects, including: a table unit which mounts a specimen to be inspected having a linearly moving stage and a rotationally moving stage; a first illumination optical unit which illuminates an inspection region of a surface of the specimen from a normal direction or in the vicinity of the normal direction while the specimen is rotating by the rotationally moving stage and moving in one direction by the linearly moving stage; a second illumination optical unit which illuminates the inspection region from a first elevation angle toward the inspection region while the specimen is rotating and moving; a first detection optical unit which detects light reflected from the inspection region by the illumination of the first illumination optical unit or the second illumination optical unit with plural detectors arranged in plural portions of a second elevation angle toward the inspection region; a second detection optical unit which detects light reflected from the inspection region by the illumination of the first illumination optical unit or the second illumination optical unit with plural detectors arranged in plural portions of a third elevation angle toward the inspection region; and a signal processor which processes signals outputted from the plural detectors of the first detection optical unit and the plural detectors of the second detection optical unit, wherein the plural detectors of the first detection optical unit and the plural detectors of the second detection optical unit are photomultipliers, and the signal processor processes the signals which are selected from the signals outputted from the plural detectors arranged in plural portions of the second elevation angle and the plural detectors arranged in plural portions of the third elevation angle.