Electronic structure of the SiC epitaxial nanolayer synthesized by a new method of the atom substitution in silicon crystal lattice has been first studied in situ in an ultrahigh vacuum using synchrotron radiation photoemission spectroscopy with photon energies in the range of 60-400 eV. Features of photoemission from the valence band and from both the Si 2p, C 1s core levels were revealed and shown to be provided by the high-quality clean SiC(111) sample with Si-rich surface. The photoemission from a surface state extending from the valence band maximum into gap was found. Three surface-related components of Si 2p core level were found. Only one surface component of the C 1s core level was found that indicates on one position of C atoms near the surface. The results support the full Si adlayer structure model of the SiC (111) surface that is characterized by Si- double layers, Si-dimers and Si adatoms.