The invention relates to a multi-dose inhaler for substances in powder form, for example comprising at least one dosring (2) with a plurality of preferably circular arranged powder chambers (1) intended for the respective dose of powdered substance, and a feed mechanism (5) that is arranged to feed the dose-ring (2) or dose-rings (2) in the intended direction of movement, with at least one seal (11,22) provided to seal the powder chambers (1) from each other and from the environment for retaining the doses of powder in each powder chamber (1). The invention is achieved by letting the advancing mechanism (5) be arranged to feed the dose-ring (2) or dose-rings (2) so that at least two powder chambers (1) at a time are moved to a position of delivery of the doses of powder, to an air channel (7) comprising at least a section (7a, b) that is arranged in the position of the powder chamber (1) that have been advanced, that the air channel (7) or its section (7a, b) is arranged to allow at least two powder chambers (1) to be opened for inhalation, substantially at the same time, in the air channel (7) so that the powder chambers (1) and their powder doses are exposed to the air channel (7) through which the powder doses are allowed to pass out through the air channel (7) and mixed with each other by means of the airflow.Linvention concerne un inhalateur à doses multiples pour des substances sous forme de poudre, comprenant par exemple au moins un anneau de dose (2) ayant une pluralité de chambres de poudre disposées de préférence de façon circulaire (1) conçues pour le dosage respectif dune substance pulvérulente, et un mécanisme de distribution (5) qui est conçu pour distribuer le ou les anneaux de dose (2) dans la direction de déplacement prévue, au moins un joint détanchéité (11, 22) étant conçu pour isoler de manière étanche les chambres de poudre (1) les unes des autres et de lenvironnement pour maintenir les doses de poudre dans chaque chambre de poudre (1). Linventi
