In this paper, an influence of processing in glow discharge hydrogen plasma on structure properties of SiC_1.4 and SnO_x thin films is investigated. SiC_1.4 layer formed by multiple implantation of carbon ions with energies 40, 20, 10, 5 and 3 keV into silicon substrate. It was found that the processing in hydrogen plasma has led in complete disintegration of silicon crystallites in transition layer “film — substrate” (“SiC–Si”) and to structure disordering of the silicon carbide crystallites in SiC_1.4 layer. SnO_x films of thickness ~350 nm have deposited by magnetron sputtering in Ar–O₂ atmosphere on glass substrate. It is shown that phase composition and structure of SnO_x films essentially depend on pressure of Ar–O₂ mixture in chamber ranged 1–2,7 Па. Various influence of hydrogen and oxygen plasmas on both segregation and disintegration processes of polycrystalline phases in SnO_x films is shown. It is shown, that the action of hydrogen plasma is spread to all depth of films (~200–300 nm), causing decay of crystal grains of silicon or tin oxide. The penetration of a quantity of hydrogen ions of plasma through a solid film guesses saturation of film material by hydrogen.