A connector includes a packing which includes an annular body part, ear parts extending outward from the body part, and lock receiving parts provided in the ear parts. The connector further includes a case which includes an annular packing-mounted part provided on which a body part of the packing is mounted, a flange part which is integrally provided on the case body part to surround the packing-mounted part, a pair of through holes which are formed in the case body part to communicate between a face of the packing-mounted part and a back face of the flange part and through which the ear parts are respectively passed, and a pair of locking parts which are provided on the back face of the flange part and with which the lock receiving parts in the ear parts are respectively engaged.