1. A method of inspecting a defect of an object to be inspected, comprising the steps of: performing a first inspection in which a whole area of the plane of the object is subjected to imaging with the use of an optical system to gain image information in relation to the plane, and then to positional detection of a particular region on the plane on the basis of the image information, the particular region having a higher luminance than a remaining region on the plane; and performing a second inspection in which the plane of the object is subjected to a detailed inspection under a microscope with reference to information indicative of a position of the particular region detected by the first inspection.