In this paper we report the development of a new method for the evaluation of thin films mass thickness and composition based on the Energy Dispersive X-Ray Spectroscopy (EDS). The method exploits the theoretical calculation of the in-depth characteristic X-ray generation distribution function (ϕ(ρz)) in multilayer samples, where ϕ(ρz) is obtained by the numerical solution of the electron transport equation. Once the substrate composition in known, this method gives reliable measurements without the need of a reference sample and/or multiple voltage acquisitions.The electron transport model is derived from the Boltzmann transport equation and it exploits the most updated and reliable physical parameters in order to obtain an accurate description of the phenomenon. The method for the calculation of film mass thickness and composition is validated with benchmarks from standard techniques. In addition, a …