An X-ray CT system according to one embodiment includes a top plate on which a subject is laid, a driver configured to drive the top plate in a lateral direction of the top plate, a frame provided on both sides of the top plate in the lateral direction, and a cover provided between the frame and the top plate, respectively. The top plate and the cover are arranged so that the top plate does not come in contact with the cover in a drive range of the top plate by the driver in the lateral direction.