Abstract: A medical device for inhaling metered aerosol has a cylindrical housing with a receiving chamber for receiving an aerosol container and first main air channels extending axially within the housing. A mouthpiece is coaxially connected to the housing. An atomizing and vortexing chamber is delimited by the housing and the mouthpiece. Second main air channels extend within the mouthpiece and communicate with the first main air channels. A partition is positioned between the receiving chamber and the atomizing and vortexing chamber. The partition has a stepped bore with a first section and a second section, the first section having a larger diameter than the second section. The first section opens into the receiving chamber and the second section opens into the atomizing and vortexing chamber to form an aerosol outlet. Branch air channels extend at a slant to an axial direction of the medical device within the partition so as to surround the stepped bore.