Terminals are inserted respectively into terminal receiving chambers in a housing, and then retaining pins of a second insertion retaining means are inserted respectively into retaining pin insertion holes in the housing, so that the terminals received and held in the housing are retained in a double retained manner. A slanting surface is formed on at least one of a distal end of each of the retaining pins and that outer surface of each of the terminals which can contact the retaining pin inserted into the retaining pin insertion hole 38, the slanting surface extending in a direction intersecting a direction of insertion of the retaining pin, and the slanting surface producing a force urging the associated terminals to move deeper in the corresponding terminal receiving chambers when the second insertion retaining means is attached to the housing.