The radiographic X-ray device according to this invention is constituted in such a way that positional relation detecting unit 25 detects in real time the information regarding the positional relations between X-ray imaging systems 4 and 8 that thoroughly represents the overall current status of the positional relations of external surfaces of both X-ray imaging systems 4 and 8 where collisions between first and second X-ray imaging systems 4 and 8 may occur, that the information regarding the positional relations detected by positional relation detecting unit 25 is taken into consideration in controlling the motions of X-ray imaging systems 4 and 8, and that the current status of the positional relations of external surfaces of both X-ray imaging systems 4 and 8 can be thoroughly and accurately reflected upon the motions of X-ray imaging systems 4 and 8 without any difficulty, so that any collisions of X-ray imaging systems 4 and 8 can be avoided without fail.