PROBLEM TO BE SOLVED: To surely prevent errors in detection of irradiation start of radiation due to noises occurring during communication.SOLUTION: An irradiation detection unit 53 includes a comparison circuit 61 and a determination circuit 62. The comparison circuit 61 compares an offset-corrected voltage signal Dave with a threshold value Dref. A control circuit 41 turns off a switching element 63 when transmission/reception operation is performed by a communication unit 34, and cuts off the connection with the determination circuit 62 to disable the function of the irradiation detection unit 53. The determination circuit 62 monitors the voltage value of an output terminal of the comparison circuit 61 to determine whether or not irradiation of an X-ray is started. When the determination circuit 62 determines that irradiation of an X-ray is started when transmission/reception operation is not performed by the communication unit 34, and the switching element 63 is turned on to enable the function of the irradiation detection unit 53, the control circuit 41 immediately shifts an FPD 36 to storage operation.SELECTED DRAWING: Figure 3
