A dry powder inhaler including a main body, a plurality of individual reservoirs, such as blisters, each containing a single dose of powder, and disposed one behind another on a flexible strip, and an opening mechanism provided for opening an individual reservoir each time the device is actuated. The device includes first a displacement mechanism adapted to displace an individual reservoir to face the opening mechanism before and/or after each actuation, and a second displacement mechanism adapted to displace an individual reservoir against the opening mechanism on each actuation. The first displacement mechanism having an indexer wheel provided with a recess that receives an individual reservoir, the recess defined by a bottom wall and an inner side wall of said indexer wheel, and by an outer side wall formed on a separate adjustment element assembled on the indexer wheel.