The regularities of the formation of thin Mn/Si (111) nanofilms during solid-phase deposition of Mn on Si under conditions of ultrahigh vacuum ([Formula: see text][Formula: see text]Pa) and thin Mn4Si7/Si (111) nanofilms during annealing of the Mn/Si system have been studied. It has been established that silicon atoms diffuse into the Mn film up to a thickness of [Formula: see text]–12 monolayers, and Mn in Si up to [Formula: see text]–10 monolayers, therefore, a transition layer of nonstoichiometric MnxSiy silicide is formed at the Mn–Si interface. After heating at [Formula: see text][Formula: see text]K, the higher manganese silicide (HMS) Mn4Si7 is formed. In particular, it was found that the bandgap of Mn4Si7is [Formula: see text][Formula: see text]eV, and the electron affinity is [Formula: see text][Formula: see text]eV and in the work, the optimal thermal diffusion conditions for the formation of stoichiometric Mn4Si7 silicide are determined. It is shown that at [Formula: see text][Formula: see text]K, a partial formation of a chemical bond between manganese and silicon atoms occurs. At 1100[Formula: see text]K, a thin Mn4Si7 film with a good stoichiometric composition is formed.