An X-ray inspection apparatus includes a conveying unit configured to convey an article, an X-ray source configured to irradiate the article with X-rays, a detection unit configured to detect the X-rays by photon counting, a threshold value setting unit configured to set a threshold value for discriminating the X-rays, an inspection unit configured to inspect the article on the basis of the X-rays transmitted through the article, the X-rays being detected by the detection unit, and a sensitivity correction unit configured to perform sensitivity correction of the detection unit on the basis of the X-rays not transmitted through the article, the detection unit is configured to discriminate and detect the X-rays into the two or more energy regions by using the threshold value, and the sensitivity correction unit is configured to perform the sensitivity correction when the threshold value setting unit changes the threshold value.