PURPOSE: To form ≥2 kinds of X-ray images having each different quality, on an image receiving body, by simple constitution, by placing a means for giving a transmission characteristic which is different from X-ray transmission characteristics, in an advancing path, and superposing and forming X-ray images having plural qualities.

CONSTITUTION: At each instantaneous time of irradiation of X-rays, X-rays irradiate a person to be inspected, from both parts A, B of a disk 11, and it is repeated alternately in the course of an operation time. Subsequently, the quality is alternated in order, X-rays which have transmitted the person to be inspected P energize sensitizing screens 3 and 5, emit fluorescent light, and expose a sheet film 15 from before and behind, therefore, on the film, an image on which X-rays passing through the part A have been indicated clearly, and an image which has passed through the part B and on which X-rays having different qualities have been indicated clearly are superposed and formed. An X-ray film obtained in this way becomes equal to that which is superposed a photograph exposed by 2 kinds of X-rays having each different quality.