To enhance S/N (signal to noise) of an image signal indicating a radiation image without lowering resolution in the case of indicating the radiation image in a radiological image reader.

A line sensor 30 consisting of a CCD element 32 having many light receiving parts 35 which are two-dimensionally arranged along the main scanning X direction as a whole is relatively transferred in the sub-scanning Y direction to be crossed with the main scanning X direction to a radiation image conversion panel 10. At this state, a stimulating light beam generated from the radiation image conversion panel 10 by irradiation of a linear stimulating light beam Le extending in the main scanning X direction is received by a plurality of light receiving parts 35A to 35E. Each electric charge received by the light receiving parts 35A to 35E and to which photoelectric conversion is performed is transferred to a horizontal transfer register 36, binned and defined as an electric charge T indicating one pixel. After that, the image signal based on the electric charge T is amplified by an amplification part 37.