In an electrical connecting apparatus, a thermal deformation restriction member, a reinforcing plate, and an auxiliary member are made of materials having smaller thermal expansion coefficients in this order, and a wiring board supporting a probe assembly is coupled with the reinforcing plate. The auxiliary member has a void inside the coupling region with the reinforcing plate. The void receives the deformed part when the center portion of the wiring board is deformed toward the reinforcing plate. Thus, the thermal deformation restriction member, the reinforcing plate, and the auxiliary member function as a three-layer bimetal having a sandwich structure, and the thermal deformation of the wiring board is restricted effectively.