A workload of a technician (operator) of a radiation image data management system employing a radiation detecting cassette is reduced. An order data reception terminal, a sensor, a transmission means and a reception means is provided within an imaging room. The sensor detects entry of the radiation detecting cassette into an area within a predetermined range of the imaging room. Order data, received from an order data management system, is automatically and wirelessly transmitted to the radiation detecting cassette from the transmission means. After imaging is complete, the order data and an image signal transmitted from the radiation detecting cassette is automatically received by the reception means.