PURPOSE: To securely bring an adapter pin into contact with an inspection point even if a printed wiring board has a slight error in manufacture, etc., by moving a fine adjusting plate where the printed wiring board is fitted slightly by a fine adjusting mechanism.

CONSTITUTION: The printed wiring board 2 is arranged on the fine adjusting plate 6 on a dedicated board 3. Then, the adapter pin 11 is fitted to the spring probe 9 of an off-grid unit and the tip part of the adapter pin 11 is made to abuts on the inspection point of the printed wiring board 2. If the tip part of the adapter pin 11 does not abut on the inspection point, a reference pin 28 is detached and X- and Y-directional fine adjusting knobs of an X-Y fine adjusting mechanism 5 which are fitted on the left and right sides of the dedicated board 3 are rotated to move X- and Y-directional fine adjusting guide pins in an X direction and a Y direction. This operation is carried on until the tip part of the adapter pin 11 securely contacts the inspection point of the printed wiring board 2.