PURPOSE: To reinforce a peripheral part of a fitting hole with a bent piece, and to eliminate the fitting directional characteristic of a material to be fitted, and to hinder the loosening of a conductive screw with the flexural elastic force after screwing the bent piece to dispense with a spring washer.

CONSTITUTION: A conductive member 5 having a bent piece 4, which is inserted to a fitting hole 2 of an insulating material 1 to be fitted made of plastic along the inner surface of the fitting hole 2 and projected a little, is arranged on the surface of the material 1 to be fitted. The material 1 to be fitted is made to contact with the surface of a conductive fitting body 7, and the material 1 to be fitted is screwed tightly by a conductive screw 9, which is inserted into a hole 8 of a conductive fitting body 7 through the bent piece 4 inside of the fitting hole 2, to deform the bent piece 4 of the conductive member 5 forcedly, and the tip thereof is connected for continuity to the inner peripheral surface of the hole 8 of the conductive fitting body 7 by the conductor screw 9.