According to the embodiment, a case supporting part supports a substrate case on an apparatus housing in a manner that allows the substrate case to move between a first position and a second position. The first position is contained in a first range extending in a predetermined direction parallel to the side surface of the apparatus housing where a maintenance target is provided closer thereto and covering also the position of at least part of the maintenance target. The second position is contained in a range extending in the predetermined direction and covering the position of the maintenance target with the range being narrower than the first range. A control substrate is arranged such that, when the substrate case is at the first position, a plurality of connections are placed at positions corresponding to the positions of respective electrical components to which the control substrate is to be connected.