Abstract: A finisher provided with a punching unit which punches a sheet. The punching unit has five punching rods, a drive shaft which rotates to drive the punching rods, five pairs of circular cam and eccentric cam which are fitted around the drive shaft and a switching board which moves the drive shaft in its axial direction reciprocally at a specified pitch. With a one-pitch movement of the drive shaft in its axial direction, three of the five punching rods (in a three-hole mode) or two of the five (in a two-hole mode) come into contact with the respective eccentric cams, and the three rods or the two rods are moved to make three holes or two holes in a sheet. The selection between the three-hole mode and the two-hole mode is automatically carried out in accordance with the sheet size.