High resolution soft X-ray photoemission measurements have been performed onto ultra thin films of hexadecafluoro copper phthalocyanine deposited, at room temperature and in ultra high vacuum conditions, onto clean Si(111)7 x 7 substrate. The Si 2p spectra show the missing of the adatoms signal and the appearance of a broad feature mainly due to F-Si bonds. The Si 2p spectrum allows us to exclude the loss of copper atom from the molecule during the deposition. C Is spectrum evidences the presence of Si-C interaction, These results confirm previously published X-ray photoemission spectroscopy fluorine spectra, which clearly present the effects of the interaction of F atoms of the molecule with the silicon substrate and a strong modification of the C Is spectrum. (C) 2001 Elsevier Science B.V. All rights reserved.