A respiratory mask (20), especially a facial mask, comprising a mask body (21) comprising an inner chamber (30) and a gas inlet (22)； a hollow curved connector (1)； and a front piece (24) comprising a central aperture (31) and headgear connecting structures (25). The gas inlet (22) of the mask body (21) and the central aperture (31) of the front piece (24) are traversed by a downstream portion (19) of the hollow connector (1). The peripheral outer wall (6) of the downstream portion (19) of the hollow connector (1) is shaped so as to present a first abutment structure (15) and a second abutment structure (16), cooperating with the front piece (24) and the mask body (21) for holding the hollow connector (1) and the front piece (24) integral with the mask body (21), when the downstream portion (19) of the hollow connector (1) is inserted into the gas inlet (22) of the mask body (21). Assembly for delivering a gas to a patient comprising a gas delivery device, such as a medical ventilator, and a respiratory mask according to the present invention.
