Abstract: The micromechanical sensor head is designed to measure forces down to 10.sup.-13 N. It comprises a common base from which a cantilever beam and a beam member extend in parallel. The cantilever beam carries a sharply pointed tip of a hard material, dielectric or not, for interaction with the surface of a sample to be investigated. Bulges forming a tunneling junction protrude from facing surfaces of said beams, the gap between said bulges being adjustable by means of electrostatic forces generated by a potential (V.sub.d) applied to a pair of electrodes respectively coated onto parallel surface of said beams. The sensor head consists of one single piece of semiconductor material, such as silicon or gallium arsenide (or any other compounds thereof) which is fabricated to the dimensions required for the application by means of conventional semiconductor chip manufacturing techniques.