1. A defect observation method, comprising the steps of: detecting defects on a specimen detected by another inspection device by a detection device having an optical microscope on the basis of positional information of the defects; amending the positional information of the defects on the specimen detected by the another inspection device on the basis of positional information of the defects detected by the detection device having the optical microscope; and observing the defects detected by the another inspection device by using an SEM (Scanning Electron Microscope) on the basis of the amended positional information, wherein the defects on the specimen detected by the another inspection device are detected by the detection device having the optical microscope in such a manner that: forming stationary waves on the specimen by allowing two illumination lights having the same wavelength to enter the same incidence plane of the specimen at the same incidence angle from directions that are opposite to each other and interfering with each other; removing scattered light components generated from minute irregularities on the surface of the specimen among scattered light from the specimen on which the stationary waves are formed by a spatial filter; detecting an image of scattered light from the specimen that are not removed by the spatial filter; and processing the detected image of the scattered light to detect the defects on the specimen detected by the another inspection device.