A terminal module (10) has a metal case (20) with a ceiling wall (21), a bottom wall (51) facing the ceiling wall (21), opposed side walls (23) extending from the ceiling wall (21) toward the bottom wall (51) and retaining pieces (24). A coil spring (40) is sandwiched between the ceiling wall (21) and the bottom wall (51). The retaining pieces (24) face each other in a direction perpendicular to a facing direction of the side walls (23) and project toward the bottom wall (51) from the periphery of the ceiling wall (21). The side walls (23) and the retaining pieces (24) are disposed alternately on the periphery of the ceiling wall (21). A spring receiving portion (26) formed by the ceiling wall (21), the side walls (23) and the retaining pieces (24) receives an end part of the coil spring (40) on the side of the ceiling wall (21).