An electronic cassette has a configuration in which a first sensor panel and a second sensor panel are sequentially arranged in a thickness direction. The first sensor panel includes a first light detection substrate and a first scintillator. The periphery of the first scintillator is covered by a moisture-proof sealing layer. The sealing layer is made of a conductive material. The sealing layer is connected to the inner surface of a housing made of a conductive material through a connection portion. Therefore, the sealing layer has the same potential as the ground potential of the housing which is a reference potential and functions as a conductor layer.