a housing body is provided with a pair of first retainers and a plurality of terminal chambers for accommodating a plurality of connection terminals . a spacer is attached to the housing body for doubly retaining the connection terminals in the housing body . the spacer is provided with a pair of second retainers which is to be engaged with the first retainers when the spacer is attached to the housing body . a pair of finger pads are respectively protruded from outer faces of both side walls of the housing body , on which an user &# 39 ; s fingers are abutted to perform connection with respect to a mating connector . the spacer is attached into a mounting hole formed in either a top face or a bottom face of the housing body so as to communicate with the respective terminal chambers and to include inner faces of the both side walls of the housing body . the width of the mounting hole is widened outwardly at portions opposing to the respective finger pads . at least a part of the first retainers are provided in the widened portion of the mounting hole .