A method of inspecting a specimen, including: emitting a light from a lamp of a light source; illuminating a specimen on which plural patterns are formed with the light emitted from the light source and, passed through an objective lens; forming an optical image of the specimen by collecting light reflected from the specimen by the illuminating and passed through the objective lens and a image forming lens; detecting the optical image with a TDI image sensor; and processing a signal outputted from the TDI image sensor and detecting a defect of a pattern among the plural patterns formed on the specimen, wherein the image detected by the TDI image sensor is formed with light having a wavelength selected from the wavelengths of the light emitted from the light source.