The invention relates to an inhalation device for powdered drugs to be received by a patient by an inhalation-caused air stream, comprising at least one powder reservoir, metering means for repeatedly metering a powder dose from the reservoir, a transportation mechanism for moving said metering means from a filling position for receiving a powder dose into an emptying position for releasing said powder dose into a powder channel, at least one activating device for manual operation by the patient, said activating device being operatively connected to said transportation mechanism such that upon operation a single powder dose is being metered, said activating device comprising a dosage key (5) acting on said transportation mechanism when pressed by the patient. The inhalation device further comprises an advancing mechanism for advancing a counter means each time the inhalation device has been activated by the patient so that a powder dose has been released into the powder channel. The counter means comprises a mechanical index coupled to a locking mechanism blocking the dosage key (5) and/or the activating device and/or the transportation mechanism after a predetermined number of metering cycles after detection of the index. Moreover, the locking mechanism includes a locking lever (7) for positive engagement with the dosage key (5) and/or the activating device and/or the transportation mechanism in the blocked condition. The inhalation device (1) is characterized in that the locking lever includes signaling means integrally formed therewith engaging the index after said predetermined number of metering cycles.