When an AEC sensor is changed, the same AEC as before changing the AEC sensor is carried out without modifying an existing apparatus. A storage and search unit of a console acquires a source ID and searches for and extracts position information of a detection field of an old AEC sensor corresponding to the acquired source ID from source information of a storage device. An electronic cassette includes plural detection pixels as a new AEC sensor short-circuited to signal lines without passing through TFTs in the same imaging plane as pixels. A detection field selecting circuit of an AEC unit of the electronic cassette selects a detection signal from the detection pixel existing at the position of the detection field of the old AEC sensor among the detection signals of the plural detection pixels.