Provided is a medium processing device including a supply portion supplying a medium, a transporter transporting the medium supplied from the supply portion, an contact portion that a tip of the medium transported by the transporter is brought into contact with, a stacker in which the medium brought into contact with the contact portion is stacked, and a processor processing the medium stacked in the stacker, in which the transporter includes a gripper that is configured to move along a transport path of the medium, grips a tip of the medium, and moves.