In a radiation detecting device having a sensor panel in which a plurality of photoelectric conversion elements are formed on one surface of a support substrate, a moisture-proof protective layer is laminated on a surface of the sensor panel on which the photoelectric conversion elements are formed, and a warp correction layer is laminated on the other surface of the sensor panel, and the moisture-proof protective layer and the warp correction layer are formed of a resin film having a drawing or extrusion direction, respectively, and bonded together so as to make the drawing or extrusion directions of both the resin films similar to each other. With the formation of the radiation detecting device, the warp of the radiation detection panel induced by a thermal displacement is prevented.