S/N ratios of two radiological images with parallax are made equal. An angle between one of two radiographing directions and a direction perpendicular to a detection plane of a radiation detector is set to be larger than an angle between the other radiographing direction and the direction perpendicular to the detection plane of the radiation detector, and the amount of radiation is controlled such that the amount of radiation reaching the radiation detector from the one radiographing direction is equal to the amount of radiation reaching the radiation detector from the other radiographing direction.
