PURPOSE: To prevent the deformation and breakage of a housing lance and perfectly detect the incomplete insertion of a terminal to a connector housing.

CONSTITUTION: A connector 1 is formed in such a manner that a terminal 3 inserted into a connector housing 2 is caught by a locking projection on the top end part of a housing lance 6 and engagingly locked in the connector housing 2 to suppress the deflection of the housing lance 6 by a terminal drop-out preventing piece 12 to be inserted from the lance top end side to the lance deflecting cavity. On the top end 8 of the housing lance 6, a stepped part 11 having a locking surface 10 turned backward the housing lance 6 is formed. The connector housing 2 has a housing inner surface protruding wall 11 having a locking opposite surface 11a capable of making contact with the locking surface 10a formed in the position nearly opposed to the locking surface 10a. When the top end of the terminal drop-out preventing piece 12 presses the top end of the housing lance 6, the locking surface 10a makes contact with the locking opposite surface 11a to regulate the position of the top end.