Abstract: A lancet device for puncturing the skin of mammals, in particular of a human, includes a punch element, a manipulator, and a bushing element for the internal, axially displaceable reception of the punch element. The punch element on its free end has a lancet, provided with a sharp tip, for intentionally entering the skin. The lancet, by means of a force acting in the axial direction on the free end of the bushing via the punch element can be made to enter the skin from the end of the bushing outward with a preadjustable momentum, and a blocking arrangement using an axially slidable sleeve inside the bushing is provided, which, once the lancet has entered the skin, prevents the possibility of a reentry by locking itself within the bushing.