The present invention relates to a face mask for inhalation, suitable for delivering a therapeutic gas or molecule as part of a treatment by inhalation. In particular, the invention relates to a mask (M) including a body (C), a wall (P1, P2, P3) of which defines an inner space (Vi) intended for engaging with a portion of the face of a user, including the nose and mouth thereof, the body (C) having a first opening (O1) which is in communication with a means (R1) for connecting to a source of a therapeutic gas or molecule, and a second opening (O2) surrounded by a lip (L1) intended to be placed against said portion of the face of the user, characterised in that said mask comprises a sealing partition (C1) which defines, in the inner space (Vi), an upper chamber (B1) intended for accommodating the nose of the user and a lower chamber (B2) containing said first opening (O1) and intended for accommodating the mouth of the user while said mask is being worn.
