An X-ray imaging device is equipped with a solid state detector, for recording image information by being irradiated with X-rays that bear image information and for outputting image signals that represent the recorded image information, and an X-ray dosage detector for detecting the dosage of irradiated X-rays. The X-ray dosage detector is provided between an X-ray source and the solid state detector, thereby enabling accurate measurement of the X-ray dosage, without being influenced by the solid state detector. In addition, the X-ray dosage detector is equipped with a photoconductive layer. Therefore, the X-ray dosage detector can be made thinner than conventional X-ray dosage detectors, which are constituted by a fluorescent plate, a light collecting field, a light transmitting plate, and a light shielding plate. Accordingly, decreases in resolution of images detected by the solid state detector can be prevented.