A radiation imaging system includes a radiation imaging cassette and a console device. A communication mode between the cassette and the console device is switchable between a wired mode and a wireless mode. Due to shortage of a battery of the cassette, the communication mode is switched to the wired mode to start charging the battery and send image data from the cassette to the console device through a cable. The console device has first and second judging sections. The first judging section judges whether or not a charge level of the battery exceeds a predetermined threshold value. The second judging section judges whether or not radiography is in progress. If it is judged that the charge level of the battery exceeds the predetermined threshold value and the radiography is not in progress, a window that indicates permission for switching to the wireless mode is displayed on a monitor.