A detection field setting unit of a console sets a detection field of detection pixels of an electronic cassette which are used to detect the dose of X-rays passing through a subject so as to correspond to each irradiation position on the basis of irradiation positions of an X-ray source set by a driving condition setting unit and ROI information such as the position and the size of a region of interest (ROI) of the subject M input through an input device and the height thereof from a radiography platform. The electronic cassette performs an automatic exposure control of detecting the dose of X-rays by the use of the detection pixels in the detection field set by the detection field setting unit of the console and automatically controlling the irradiation dose of X-rays on the basis of the detected dose, when performing a radiographing operation at the irradiation positions.
