In nanoprobing measurements the quality of the electrical contact strongly depends on the contact force. Probing semiconductors such as silicon requires applying very high and stable forces to establish an ohmic contact between the probe tip and the structure under study. Therefore, a compact force control system is needed for nanoprobing measurements inside a high-resolution scanning electron microscopy (SEM) system. In this work we have developed an optical force measurement system (OFMS) for nanoprobing based on the reflection of a laser beam from a mirror of the probe towards a position-sensitive photodiode detector (PSD). The system principle is similar to the so-called optical-lever principle used in atomic force microscopy (AFM). However, geometrical restrictions of the SEM chamber and adjacent probes require the incident and reflected laser beams to be on the same plane as the probe cantilever. This is achieved by placing a small mirror element perpendicular onto the cantilever surface. The use of high-precision nanomanipulators with OFMS allows to position probe tips on a selected structure on a macroscopic-scale sample with nanometer precision. The slim design of the nanomanipulator and the OFMS system allows to place several force controlled tips on the same nanostructure.