A relay terminal block fixed to a fixing part by a screw includes a main body having a first surface facing the fixing part, and a second surface on a rear surface side of the first surface. The main body is formed with a recessed portion depressed from the second surface toward the first surface, a through-hole formed from a bottom surface of the recessed portion through to the first surface, and a protrusion that is provided at an edge of the recessed portion to protrude in a direction away from the second surface. The through-hole is formed to have an inner diameter larger than an outer diameter of a shaft of the screw and smaller than an outer diameter of a head of the screw, and the recessed portion is formed to have an inner diameter larger than the outer diameter of the head of the screw.