X‐ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) were used to characterize the air‐exposed and sputter‐cleaned surfaces of glow‐discharge‐produced Si1−xCx:H (x=0.05 to 0.90) films. On the air‐exposed surfaces, silicon was preferentially oxidized with the enriched carbon existing as graphite or hydrocarbon. Signal intensities obtained from the surfaces sputter cleaned with 1 keV Ar+ion beams indicated no significant preferential sputtering of C to Si for these films. The values of the carbon 1s and silicon 2pand 2sbinding energies as well as the valence band spectra suggested a significant change in the local atomic configurations atx∼0.6–0.7. Based on these XPS and AES results and the reported IR absorption data, a slightly cross‐linked, carbon and hydrogen substituted polysilicon and an almost fully cross‐linked, silicon and hydrogen substituted polycarbon were proposed to describe the structure of films below and abovex∼0.6–0.7, respectively.