The X-ray inspection device includes: an X-ray source with a focal spot size greater than the diameter of a defect for irradiating a sample with X-rays; an X-ray TDI detector arranged near the sample and having long pixels in a direction parallel to the scanning direction of the sample for detecting the X-rays emitted by the X-ray source and passing through the sample as an X-ray transmission image; and a defect-detecting unit for detecting defects based on the X-ray transmission image detected by the X-ray TDI detector.