A cassette accommodating device accommodates cassettes with various sizes. Each cassette houses a rechargeable battery and a radiation detection unit that generates a radiographic image according to an amount of received radiation and each cassette is provided with a power receiving unit for recharging the rechargeable battery on at least one of two connected side faces of each cassette. The device includes a groove portion formed with a sloping face that faces one of the two connected side faces of an accommodated cassette and a bottom face that faces another of the two connected side faces of the accommodated cassette. The bottom face is inclined such that the cassette moves toward the sloping face when the cassette is loaded. A power supply unit is formed to the sloping face and/or the bottom face so as to supply power to the power receiving unit when the cassette has been accommodated.
