In order to prevent misdetection and erroneous detection by clearly determining only a contrast caused by a foreign matter, there are provided an X-ray inspection method and an X-ray inspection device including: an X-ray tube (11) for irradiating a measurement sample with a characteristic X-ray having energy lower than an X-ray absorption edge of one element contained in the measurement sample and having energy higher than an X-ray absorption edge of a detection element; an X-ray detector (13) for receiving a transmission X-ray obtained when the X-ray passes through the sample; and an operation portion (15) for obtaining a contrast image from a transmission image of the transmission X-ray.