The invention relates to the field of inhalation devices for liquids. In particular, the in- vention relates to an improved seal construction for an inhalation device having a neb- ulizing nozzle and a piston which moves relative to a pumping chamber in order to generate pumping pressure and to an inhalation device comprising such seal.5 An inhalation device for medically active liquids (F) for generation of an aerosol com- prises a housing (1), an impingement-type nozzle (6) for generating the nebulised aer- osol by collision of at least two liquid jets, the nozzle (6) being firmly affixed to the user- facing side of the housing (1) such as to be immobile relative to the housing (1), inside the housing (1) the inhalation device comprises a reservoir (2) for storing a liquid (F), 10 a pumping device with a pumping chamber (3) for generation of a pressure inside said pumping chamber (3), wherein the pumping chamber (3) is fluidically connected with the reservoir (2), a riser pipe (5) which can be received with at least one reservoir- facing, interior end (5A) in said pumping chamber (3), and said nozzle (6) which is connected liquid-tight to an exterior end (5B) of the riser pipe (5), wherein the interior 15 volume of the pumping chamber (3) is changeable by means of relative motion of the pumping chamber to the riser pipe (5) or vice versa. A gap (10) can be present between an outside of said riser pipe (5) and an inside of said pumping chamber (3), and a seal (9) bridging said gap (10) in order to minimize pressure loss when a pressure is generated inside said pumping chamber (3).20 Said seal (9) can be fixed to said outside of said riser pipe (5), and be moveable with respect to said inside of said pumping chamber (3).L'invention se rapporte au domaine des dispositifs d'inhalation pour liquides. En particulier, l'invention concerne une structure d'étanchéité perfectionnée pour un dispositif d'inhalation ayant une buse de nébulisation et un piston qui se déplace pa
