a circuit board on one surface of which a reinforcing plate is mounted and on the other surface of which a plurality of first electric connections are provided;

a probe board disposed at a distance from the other surface of said circuit board, on one surface of which facing said circuit board second electric connections corresponding to said first electric connections are provided and on the other surface of which a plurality of probes respectively electrically connected to the corresponding second electric connections are provided;

an elastic connector having plural pairs of both contacts capable of contacting the mutually corresponding first and second electric connections of both boards and receiving a biasing force toward separating directions of both contacts of each pair;

a screw member for integrally combining said reinforcing plate, circuit board, elastic connector and probe board; and

a spacer member for keeping said probe tips on an imaginary plane by tightening said screw member;

wherein a spacer plate for adjusting a distance from said other surface of said circuit board to said imaginary plane where said probe tips are located is inserted between said reinforcing plate and said circuit board; and

wherein said spacer member is disposed so as to penetrate at least said reinforcing plate and circuit board in the thickness direction, and on said one surface of said probe board, an anchor portion is provided, with which the end portion of said spacer member is brought into contact and into which the front end of said screw member is screwed.