MgF2 is a current material for the optical applications in the UV and deep UV range. Nevertheless, modern applications still require improvement of the optical and structural quality of the deposited layers. In the present work, the composition and microstructure of MgF2 single layers grown on Si [100] substrate by physical vapour deposition (PVD) and ion beam sputtering (IBS) processes, were analyzed and compared. Experiments were carried out using X-ray photoelectron spectroscopy (XPS) in depth profile, grazing angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). Both layers exhibited a good stoichiometry and a low level of contamination. The sample grown by IBS revealed more homogeneous and regular columnar microstructure than the other one.