In a radiographic imaging apparatus, a radiation image of an object is detected by use of one of first and second electronic cassettes, to input the radiation image to the console device. The first electronic cassette is changed over between a normal transmission mode and a relay transmission mode. In the normal transmission mode, the radiation image is transmitted through a path from the first electronic cassette to the console device, and in the relay transmission mode, the radiation image is transmitted from the first electronic cassette to the second electronic cassette wirelessly and then from the second electronic cassette to the console device. Transmission of a radiation image can be performed reliably without unwanted interruption, because an indirect path of the relay transmission mode can be used even upon occurrence of a technical problem of inefficiency in the normal transmission mode.
