Disclosed is a connecting piece for artificial respiration. The connecting piece comprises an opening that faces a ventilation hose, an opening disposed toward a patient interface, and an opening to the atmosphere which can be at least partially closed from the inside by a diaphragm. The connecting piece further has a diaphragm opening for accommodating the diaphragm into the connecting piece, the diaphragm being held via a diaphragm ring that surrounds the connecting piece.
