A male housing (20) is provided with cavities (23) for inserting male terminal metal pieces (10) in two upper and lower stages and a retainer mounting hole (27) opening the respective cavities (23) in a lower direction and in two side directions. The retainer (40) is mounted movably and skewedly to a direction of inserting and drawing the male terminal metal piece (10) between a full locking position permitting to insert and draw the male terminal metal piece (10) and a regular locking position locked to the male terminal metal piece (10).