To ensure satisfactory sensitivity and to form an X-ray image having improved image quality even under slight replenishment of a developing soln. and a fixing soln.

The sensitive material has photosensitive silver halide emulsion layers on both sides of the substrate. The emulsion layers is composed of silver halide particles having 15-100mol% silver chloride content and particles having an aspect ratio (diameter of circle having the same area as projection one/thickness) of 2.0 to 25 and 0.01 to 0.35μm average thickness account for ≥30% of the total projection area of all silver halide particles in the emulsion layers. The total amt. of silver applied in the emulsion layers is 1.0 to 3.2g/m2. Further, this sensitive material has such sensitivity that exposure required to regulate density measured in the emulsion layer on the exposed side to (the min. density)+0.5 is 0.010-0.035lux.sec. The density is measured after the sensitive material is exposed with monochromatic light having the same wavelength as the wavelength of the main light emission peak of a radiation intensifying screen and having 15±5nm half-width, it is developed and the emulsion layer ion the unexposed side is peeled.