Аннотация:The relation between molecular energy spectra and transport characteristics properties of monomolecular singleelectron tunneling transistor based on this molecule were investigated. In order to approach it we first calculated single-electron molecular energy spectra of small molecules of carborane C2B10H12, fullerene C60 and platinum molecular cluster Pt5(CO)6(PPh3)4 for their different ground and excited charge energy states. Effective capacitance parameters and transport spectrum of single-electron states of each of the molecules were established and the concept of molecular transport spectra was introduced. Using Monte Carlo simulation method we calculated transport characteristics of monomolecular single-electron transistor and gave a brief comparison with available experimental data.