The electron penetration through thin films of PMMA has been simulated using two different Monte Carlo approaches. One approach is conventional, in that the energy loss of the electron along its trajectory is computed using the continuous‐slowing‐down approximation. The statistical nature of inelastic scattering events, as well as the elastic scattering events, is taken into account in the second approach, which is based on an extension of Gryzinski’s semiempirical expression for the excitation of core electrons and also the excitation of valence electrons through the use of an appropriate mean binding energy. The energy distribution of transmitted electrons through PMMA films of various thicknesses obtained by both methods are compared. The second approach is shown to give a more realistic answer for the transmitted electron energy distribution.