Abstract <p>The results of the study of the density of electronic states of the conduction and valence bands of copper phthalocyanine films on the MoO₃ surface are reported. The MoO₃ surface has been formed by magnetron sputtering and the organic film has been obtained by thermal vacuum deposition with a gradual increase in its thickness to 10 nm. The mutual energy positioning of the main maxima of the electron energy bands has been established by total current and ultraviolet photoelectron spectroscopy. It has been established from the measurement results that the electron work function of the MoO₃ substrate surface is relatively high (5.8 eV), while after deposition of the copper phthalocyanine film, the electron work function decreases to 5.2 eV.</p>