Instrument for producing a sample of body liquid for analysis by piercing the skin with a lancing element (12) having a skin piercing tip. The instrument (11) has a housing (13) and a lancing drive (14) for driving a lancing element (12) connected thereto in a puncturing movement. A pressure ring (1) surrounds a skin contact opening (4) and is adapted for pressing against the skin such that the skin (3) bulges into the opening (4) for promoting expression of body fluid. The skin contact opening (4) has an opening area corresponding to a circle with a diameter of at least 3 mm and at most 8 mm, and the instrument comprises a pressing force control device (37) for controlling the pressing force between the pressure ring (1) and the skin (3) at the time of triggering the puncturing movement, to be at least 3 N and at most 8 N.