Exposure of Langmuir-Blodgett (LB) films of fatty acid salts of bivalent metals to an atmosphere of H2S allows to form in them small particles of metal sulphides, such as CdS, PbS, CuS etc. Different investigation techniques allow one to estimate the sizes of the particles to lie within the nanometer range. The particle sizes are suitable for the formation of junctions displaying monoelectron phenomena. The junctions were formed using scanning tunnelling microscopy (STM), which allowed to localise the particle position on the graphite substrate. Then voltage-current (V-l) characteristics were measured using graphite as the first electrode and the STM tip as the second one. The shape of the V-I characteristic curves revealed monoelectron phenomena in such junctions at room temperature. The specific electronic properties of the particles, such as the bandgap, turned out to be non-critical for the origin of the phenomena.