The invention concerns a device for collecting body fluids which has at least one lancet comprising a lancet body with at least two tips of different lengths. The device is characterized in that it has a selection means with the aid of which only one tip is selected before the lancing. This selection means can have different functions and shapes. The selection means is used to select a tip from a plurality of lancet tips which have different lengths and make only this tip available for use in the lancing process. Since the various tips are attached to a lancet body, it is, for example, possible to use a bending element which bends one of the various tips out of the plane of the lancet body in order to provide only one lancet tip for use. This is especially preferable for lancet tips that are arranged linearly relative to one another.