Detailed knowledge of mechanisms of electron scattering and its practical consequences for very low energies are of prime importance for not only measurement techniques but also development of new materials for next-generation electronic devices. Determining inelastic mean free path (IMFP) of electrons in bulk materials is an ongoing topic in spectroscopy. Information on IMFP for very low electron energies, E ≤ 100 eV, is not satisfactory and it is often missing in case of 2D materials, which are promising in the semiconductor industry. Low thickness of 2D crystalline materials motivated us to develop the unique UHV device analyzing samples via transmitted electrons in a standard microscopic regime (energy range 0 – 5 keV), and also via time-of-flight (ToF) method (focusing on energy range E ≤ 300 eV). Our study of the IMFP will utilize our unique experimental device complemented with DFT simulations.