A coupling portion is approximately U-shaped with two side plates extending up from a bottom plate. Front and rear ends of the bottom plate are respectively joined to a bottom wall of a box and a mounting plate of a crimping portion. Front and rear ends of the side plates are respectively joined to side walls of the box and crimping pieces of the crimping portion. In the crimping portion, an electric wire is crimped by wrapping the first crimping pieces around a terminal portion of the electric wire mounted on a mounting plate while deforming and bending them. In respective end edges of the side plates in an upward extending direction, reinforcing portions are formed continuously extending from respective front ends that are joined to the side walls to rear ends that are joined to the crimping pieces and having regions that are bent inward.