An apparatus and method for inspecting defects includes an illuminator for irradiating light having an ultraviolet wavelength emitted from a light source onto a specimen through a reflection objective lens, an image-former for forming an image of light reflected from the specimen by the illumination of the light from the illuminator, which is passed through at least the reflection objective lens, a detector which detects the image of light formed by the image-former with an image sensor, and an image processor for processing a signal output from the detector to detect defects on the specimen. The image sensor is a reverse-surface irradiation type image sensor.