This invention is to provide a connector for use in connection of a wire harness and the like, a structure of a connector housing and a terminal locking member to be coupled thereto which can prevent the after-removal of a terminal to be inserted into a terminal accommodating chamber provided in the connector housing. According to the present invention, in the inner surface of the side wall of each terminal accommodating chamber provided in a connector housing, there is formed a guide groove which is used to guide the- two outsides of a pair of flexible locking pieces, respectively provided in a terminal locking member.