Local electronic structures of C60-Co mixture films were studied by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. XPS spectra of the C60-Co films show binding energy shifts and broadenings compared to those for a pure C 60 film in the C1s main and satellite peaks. XPS spectra in the valence region suggest an appearance of new components at near the Fermi level. NEXAFS spectra of the C60-Co film also show small shifts and broadenings of absorption peaks at C 1s → π* excitations. These results are attributed to the formation of hybridized molecular orbitals with a back donation between Co 3d and C60 π orbitals.