First principle calculations based on density functional theory by the pseudopotential method, by use of Local Spin Density Approximation in AtomistixToolKit program carried out to define band gap, density of states, total energy, magnetic moments, number of electrons, Fermi levels of Cd1-xFexTe. Cd1-xFexTe epitaxial films on glass substrate were obtained. Absorption and transmission spectra were investigated. It was defined, that with an increase in Fe concentration there is an increase in the band gap.