Abstract: This invention relates to dispensing apparatus for use with pressurised dispensing containers and in particular, but not exclusively, for apparatus for dispensing orally inhaled medicinal products in aerosol forms. The apparatus comprises a housing (4) adapted to receive a pressurized dispensing container (2) and a mouth piece (11). Valve means (28) is provided, moveable between a first position in which a duct is closed and a second position in which a duct is open, and a flow sensor being activatable, by means of an air flow created when a user applies suction to the mouth piece, to move the valve means (28) into its second position. Wherein the flow sensor comprises a diaphragm (60) and the diaphragm and/or housing is provided with at least one aperture (64), wherein the diaphragm comprises a first element (66) connected to the housing and a second element (62) axially slidably moveable relative thereto. The first and second diaphragm elements being connected by a flexible member (61).