In an X-ray imaging system, first X-ray irradiation and second X-ray irradiation are performed in performing X-ray imaging once. A preview producing circuit subjects first image data outputted from a sensor panel after the first X-ray irradiation is finished to binning processing or thinning processing to produce a preview image. The produced image is transmitted through a communication I/F to a console while the sensor panel performs an accumulation operation in the second X-ray irradiation. The preview image is displayed on a monitor of the console in the second X-ray irradiation.