PURPOSE: To prevent erroneous connection, with a higher operability, by making a fixture having a first connector linked to a probe abut on a positioning member of the body at the connection so as to be positioned and connected to a second connector linked to a circuit of the body.

CONSTITUTION: A fixture 10 is formed in a box so as to mount printed circuit board to be inspected thereon and a tapered surface 11 is also formed at one corner thereof. A probe 12 is buried in the fixture 10 and is energized upward with a spring. A connector 13 is fixed on one side surface (in X way) and a terminal 13a is connected to the probe 10. Furthermore, a positioning hole 14 is formed to be mated with a positioning pin 35 of a connection unit 30 and a positioning hole 15 to be mated with a fixture locking pin 23a of the body 20. A lever 32a of a toggle lamp 32 of the unit 30 is turned to move the body 30 to the fixture 10 so that the connector 13 will be positioned and connected to a connector 34 of a unit 30. This can prevent erroneous connection, with a higher operbility.