A transport mechanism includes a transport belt in which holes are formed and a suction clinging mechanism. The transport mechanism transports the medium in the first transporting direction, and when the upstream edge reaches a switching position, the transport mechanism transports the medium in the second transporting direction and stacks the medium in a stacker. The suction clinging mechanism includes an opening of a first suction chamber and an opening of a second suction chamber, and the opening of the first suction chamber is located downstream of the opening of the second suction chamber in the first transporting direction. The switching position is located upstream of the opening of the first suction chamber in the first transporting direction. In the first transporting direction, the distance from the switching position to the opening of the first suction chamber is longer than the length of each hole.