The synthesis of nanostructured powders and films based on rare-earth ferrite garnet Sm3Fe5O12 was carried out with hydrothermal as well as with the method of precipitation of aqueous solutions of nitrates on the substrate surface. Using atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy (Raman), and X-ray phase analysis (XRD), the topology of the surface and the phase composition of the samples were studied. According to AFM and SEM, particle sizes were evaluated and the structural features of powders and films were analyzed. Raman spectroscopy (RS) and X-ray phase analysis were used to examine the chemical composition and crystal structures of synthesized samples. The possibility of simultaneous investigation of the same sample area with AFM methods and Raman spectroscopy made it possible to obtain data of the chemical composition, the presence of impurities and defects, and the shape of macromolecules. Taking into account the set of obtained results, it is shown that materials based on Sm3Fe5O12, due to their structural features and physics-chemical parameters, can be used as filters for industrial sewage treatment.