Nitride layers were grown on a SiC surface by thermal nitridation using a mixed gas of NH3 and N-2. The thermal nitridation was carried out at 1000degreesC and 1090degreesC under the atmospheric pressure. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface layer. The F peaks from Si2p, C1s, N1s and O1s were observed in the XPS spectra. These peaks showed that the surface layer consisted of Si, N, C and O. The thickness of the surface layer was estimated at less than 10 nm.