The growth of PbSe layer on Si(111) substrate via a CaF2 thin buffer layer was realized by Molecular Beam Epitaxy (MBE). The process for forming native sulfide films by chemical and anodic sulfidization is described. These methods, frequently used for III-V and II-VI materials, have not been yet studied for the PbSe surface passivation. The structural characterizations were realized by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and atomic force microscopy (AFM). A comparative study between MBE. air exposure and passivated surfaces is developed. An AES semi-quantitative calculation allows to estimate the sulfur penetration thickness of about 15 Angstrom. The good chemical passivation and the stability in the time is shown.