Fluid dispensing device, comprising a body (10), at least one individual reservoir containing a single dose of fluid, such as powder, opening means (80) being provided for opening an individual reservoir at each actuation of the device, the device comprising an inhalation nozzle (5) and an inhalation triggering system (60) which comprises a deformable air chamber (61) cooperating with said inhalation nozzle (5) and a a trigger element (600) cooperating with said air chamber (61), so that upon inhalation through said inhalation nozzle (5), said air chamber (61) is deformed and said trigger member ( 600) actuates said opening means (80), so that a reservoir is opened by said opening means, said air chamber (61) having a deformable lateral body (611), a first open end having a peripheral edge (62) surrounding one or aperture forming the inlet of said hollow pocket, and a second end forming the bottom of said hollow pocket, said second end having connecting means (63) for connecting said air chamber to said trigger member (600), said lateral body (611) being bellows-shaped having a plurality of bellows portions (611a, 611b, 611c, ...), advantageously six, arranged axially one after the other, said bellows-shaped lateral body (611) having bellows parts having different outer and / or inner diameters.Dispositif de distribution de produit fluide, comportant un corps (10), au moins un réservoir individuel contenant une dose unique de produit fluide, tel que de la poudre, des moyens d'ouverture (80) étant prévus pour ouvrir un réservoir individuel à chaque actionnement du dispositif, le dispositif comportant un embout d'inhalation (5) et un système de déclenchement par l'inhalation (60) qui comporte une chambre d'air déformable (61) coopérant avec ledit embout d'inhalation (5) et un élément déclencheur (600) coopérant avec ladite chambre d'air (61), de sorte que lors d'une inhalation à travers ledit embout d'inhalation (5), ladite chambre d'air (61) est déformée et ledit élé
