DEFECT INSPECTION DEVICE

The invention includes a pulse oscillated light source, an illumination unit that guides light output from the light source to a sample, a scanning unit that controls a position at which the sample is scanned by the illumination unit, alight converging unit that converges light reflected from the sample, a first photoelectric conversion unit that outputs an electric signal corresponding to the light converged by the light converging unit, an AD conversion unit that converts the electric signal output from the first photoelectric conversion unit into a digital signal in synchronization with pulse oscillation of the light source, a linear restoration unit that processes a digital signal converted by the AD conversion unit in synchronization with a pulse oscillation output by the AD conversion unit and corrects nonlinearity of the first photoelectric conversion unit, a defect detection unit that detects a defect of the sample based on an output of the linear restoration unit, and a processing unit that obtains and outputs a position and a size of the defect detected by the defect detection unit.