A new instrument for surface pressure measurements using a floating‐foil technique has been constructed. The instrument makes use of a probe in the form of a thin foil suspended at the gas/liquid or liquid/liquid interface tension. The present instrument has a dynamic range of 0.1–70 mN/m and a sensitivity better than 0.1 mN/m. Its speed of response is 50 ms but much faster measurements are possible. Measurements on behenic acid and cholesterol films on water and on a cerebroside film at a heptane/water interface are presented.