Nanopowders and thin films of (CeO2)(1-x)(Y2O3)(x) composition (x = 0.10, 0.15 and 0.20) were obtained by the sol-gel process, using hydrolytically active complexes of the metal alkoxoacetylacetonate class [M(C5H7O2)(3-y)(C5H11Oi)(y)] (M = Ce3+ and Y3+) as precursors. The impact of the chemical composition and crystallization conditions on the microstructure, electrophysical and chemosensory characteristics of the obtained planar-type solid electrolytes was studied. The prospects of the thin-film nanostructures obtained as receptor components of resistive oxygen sensors, as well as of electrolytes of planar-type intermediate-temperature solid oxide fuel cells (SOFC) have been shown. It has been found that (CeO2)(0.90)(Y2O3)(0.10) thin films demonstrate the maximum values of electrical conductivity (550 degrees C) and the highest sensory response when detecting oxygen (concentration range 1-20%, operating temperature range 300-450 degrees C).