The invention relates to a step-by-step mechanism, particularly for hand-helddevices (1) for the portioned delivery of medicaments to be inhaled,comprising a graduated collar (26), which can be moved during an actuationstroke and which encircles the center axis of the housing (34). In order toprovide a step-by-step mechanism of the aforementioned type with a morereliable operation while, in a spatially advantageous manner, having asimplified design, the invention provides that the switching finger(s) (S, 28)are permitted to slope upward from a hub (29) located in the center.
