An apparatus includes a discharge mechanism including a drive roller rotatable in a normal direction to discharge a medium and in a reverse direction reversed to the normal direction, and a driven roller in contact with the drive roller and configured to be rotated by the rotation of the drive roller. The apparatus also includes a stacker on which the medium discharged from the discharge mechanism is to be stacked. The driven roller is movable in position depending on the rotation of the drive roller in the normal direction or the reverse direction, such that the driven roller is located at a first position in the vicinity of the stacker when the drive roller is rotating in the normal direction, and the driven roller is located at a second position further away from the stacker than the first position when the drive roller is rotating in the reverse direction.