PURPOSE: To improve the tight contact between an intensifying screen and a film by bulging a supporting member for the front intensifying screen beforehand to the rear intensifying screen side in such a way that the front intensifying screen comes to the front surface when roughly uniform load by the rear intensifying screen is applied upon the front intensifying screen.

CONSTITUTION: A rear intensifying screen 26 is supported via a cushion 27 on a base plate 29 without using any spring to a rear part 22. An intensifying screen plate 25 is bulged to the screen 26 side with the central part of its two sides 25a, 25b as a center. Since the rate of the bulging can be determined from the values of the Young's modulus and geometrical moment of inertia of the supporting plate 25 for the front intensifying screen, the rate of bulging is determined by said values. If the part 22 is pressed to a front part 21 in the stage of sandwiching a film, the screen 24 which is bulged to the shape determined beforehand by calculation is deformed by this pressing, and when the sandwiching is completed, said screen is made roughly flat, whereby a good X-ray image is obtained.