The present invention relates to a device for administering dry powder inhalation medicaments. The present invention further relates to a counter mechanism of a dry powder inhaler device (6), comprising an actuating element (5), which is slid or pushed into the interior of an inner body, so as to move a blister (4) in a single direction, said blister having medicament-carrying cavities being disposed in the interior of an outer housing (1) and directed both to an inner body (2) and to a mouthpiece (3). The strip comprises numbers to indicate the sequential numbers of said blister cavities (4.1), and an arc shaped surface piece (2.1), forming a channel through which the blister (4) is to be passed at the lower part of the inner body (2) and keeping the blister (4) at a desired stretched extent in this channel.