PROBLEM TO BE SOLVED: To ensure that the output of a pixel for a radiation dose detection is effectively utilized in image generation without being wasted with a simple configuration and control of a radiation image detection device.SOLUTION: An FPD 35 includes a pixel 36 used for image detection and a detection pixel 58 used for reached radiation dose detection. Simultaneously when X-ray radiograph starts, a TFT 57 of the detection pixel 58 within a lighting field is turned on. A radiation dose detection signal based on electric charge from the detection pixel 58 within the lighting field and an irradiation stop threshold are compared, whereby time to stop X-ray irradiation is estimated by an AEC unit 52. When the estimated time is calculated, the TFT 57 of the detection pixel 58 within the lighting field is turned off, letting electric charges accumulate therein. After the X-ray irradiation has stopped, the FPD 35 is driven to execute a readout operation, and an image signal is thereby output. The image signal of the detection pixel 58 within the lighting field is corrected by multiplying it by a ratio Ta/Tb of an electric charge accumulation time Ta of the image signal of the pixel 36 to an electric charge accumulation time Tb of the image signal of the detection pixel 58 within the lighting field in a multiplication circuit 69. The corrected image signal and the image signal of the pixel 36 and the detection pixel 58 outside the lighting field are used to generate an X-ray image.
