A fuser allows a sheet medium on which a toner image has formed to path through while heating the sheet medium, thereby fusing the toner image on the sheet medium. The pan is generally circular and includes a sealable radial slot to receive the shaft of a jack supporting the object. However, custom designs are more expensive in terms of testing and development time. When the probes are made contact with electrodes of a semiconductor device of the semiconductor wafer by moving up the mounting table, the contact portion and the electrode plate are made contact with each other and the backside electrode and the tester are electrically connected to each other.