Provided is a method wherein a multi-anode detector is used for the purpose of detecting scattered light from a wafer, data obtained from the detector (multi-anode) for detecting defects is used, the shape of a beam radiated to the wafer, a rotational shift between the radius direction and the beam long side, and the like are calculated, and the optical axis of the irradiation beam is adjusted. Furthermore, the method is provided with a technique which feeds back the correction quantities for rotation and amplitude to inspection signal data, on the basis of the correction data, and corrects inspection data. Since fine correction with the adjustment of an optics system and signal processing is made possible, positional accuracy of defect inspection and accuracy of defect level (defect size) are improved.