A first power supply unit supplies power to a first sensor panel and a first circuit unit. A second power supply unit supplies power to a second sensor panel and a second circuit unit. A synchronizing signal supply unit of a control unit supplies a synchronizing signal for synchronizing the operations of a switching power supply of the first power supply unit and a switching power supply of the second power supply unit to the switching power supply of the first power supply unit and the switching power supply of the second power supply unit. Since the operations of the first and second power supply units are the same in each imaging operation, it is possible to ensure the reproducibility of an X-ray image.