A resistor includes: a first resin protruding part formed in the bottom surface of an exterior material (mold resin body), on an end opposite to a leading side of harness wires along the length of the exterior material near a through-hole piercing an upper surface and a lower surface of the exterior material, and a second resin protruding part, surrounding the circumference of a metal bush embedded in the through-hole and the entire circumference of the resistor substrate. Moreover, a concave part is formed in a region sandwiched between the first resin protruding part and the second resin protruding part.