A respiratory mask (30) is disclosed. The respiratory mask (30) comprises a mask body (32,132) defining a cavity and being adapted to fit about the mouth and/or nose of the patient, such that a respiratory gas can be inhaled by the patient from the cavity. The respiratory mask (30) also has a plurality of separate ports (42,44) for enabling passage of gas into, and out of, the cavity of the mask body (32,132), and a valve assembly (40,140). The valve assembly (40,140) includes a continuous valve membrane (50,150) having a deformable first valve member (52,152) that controls flow of gas through a first port (42), and an independently deformable second valve member (54,154) that controls the flow of gas through a second port (44).
