The inelastic mean free paths (IMFPs) of electrons at a poly[methyl(phenyl)silylene] thin film surface were determined using elastic peak electron spectroscopy (EPES) and Monte Carlo calculations for a wide electron energy range, 200-1600 eV. We considered the surface composition determined from X-ray induced photoelectron spectra (XPS), the hydrogen concentration evaluated by EPES, and a correction for Surface excitations. The results compare well to those calculated from the predictive TPP-2M and G1, formulae. Calculations carried out with the quantitative structure-property relationship of Cumpson and the formula of Ashley and Williams provide larger IMFP values, and can be useful only for a rough estimation. (C) 2009 Elsevier Ltd. All rights reserved.