Abstract: The present invention provides an X-ray inspection device that detects a defect not on the basis of a change of an X-ray irradiation angle but on uniform determining criteria. As one embodiment for achieving the purpose, proposed below is an X-ray inspection device that is provided with: a detection element that detects a transmission X-ray, which has been emitted from an X-ray source and passed through a sample; and an arithmetic device, which forms a profile on the basis of output signals transmitted from the detection element, and which detects, using the profile, a defect included in the sample. The arithmetic device detects the defect on the basis of threshold setting corresponding to the visual field positions of the transmission X-ray.