A dosing device can be activated by a vacuum air stream of a user for the inhalation of a powder substance, particularly medicine, which is arranged in a supply chamber and which can be brought out of the same into an open emptying-ready position by a dosing chamber of a dosing rod when the mouthpiece-closure cap is removed. In particular, in order to improve dispensing, the provision of two air paths, of which one serves to open and empty the dosing chamber, and/or the second air path penetrates directly into a ring chamber in order to mix with the air flow containing the substance.