Nanosized structures and their specific properties are of great interest in nanoelectronic applications. As a result of the nanoscaled dimensions, quantum effects are becoming important, opening new applications particularly with regard to semiconductor technology, such as quantum dots in semiconductor structures. Established methods to generate nanoscaled structures, like the self-organized growth of quantum dots by the Stranski-Krastanov mode, are often limited in terms of material, size and deposition density of quantum dots. A possibility to overcome this restriction is the deposition (and subsequent embedding) of pre-produced nanoparticles within a semiconductor structure. In the presented study, the size-selected deposition of Indium nanoparticles on semiconductor surfaces is demonstrated. The particles were synthesized in a microwave flow reactor and extracted from the reaction zone by molecular beam sampling. A particle mass spectrometer was used to size-select particles from the molecular beam for deposition on various surfaces. The desired particle size was selected by adjusting the voltage of the deflection capacitor. The pre-selected particle diameter was in very good agreement with the diameter obtained from TEM analysis of the surface-deposited particles. The particles were spherical, monodisperse (standard deviation below 1.1) and non-agglomerated. The method described in this work allows the deposition of any gas-supported nanoparticles on almost all solid surfaces. Due to the operating pressure of 10-5 mbar and less, this method enables the combination of epitaxial growth processes with nanoparticle deposition techniques and provides access to a rich variety of material combinations.