To provide a connector 10 which can surely regulate the movement of a stopper ring 50 and a pipe at a normal connecting position of the pipe while simplifying a mechanism for rotating the stopper ring 50.

The connector 10 includes: a housing 20, the stopper ring 50 having an engagement claw 53 for locking the pipe P, and a checker 70. The connector 10 further includes a rotating mechanism provided to be cooperative with the stopper ring 50 and the checker 70, the rotating mechanism rotating the stopper ring 50 from a temporary rotating position to a rotation completion position within a connecting hole 25 by the moving force of the checker 70 from a temporary fixing position to a detecting position; and a regulation mechanism provided to be cooperative with the stopper ring 50 and the checker 70, the regulating mechanism regulating the movement of the stopper ring 50 when the checker 70 is in the temporary fixing position and in the detecting position.