The results of a study of the structure and electrical properties of SrCe0.95Yb0.05O3 thin film protonic conductors are presented. Dense SrCe0.95Yb0.05O3 thin films (similar to 1000 nm) with grain size in the 30-70 nm range were obtained on Si- and Al2O3-substrates using a polymeric precursor spin coating technique. The electrical conductivity of these thin films has been studied as a function of temperature and correlated with the microstructure. The thin films showed higher electrical conductivity than dense sintered polycrystalline SrCe0.95Yb0.05O3 specimens which had grain size in the micrometer range. This electrical conductivity enhancement has been attributed to the influence of interfacial grain boundary effects in the films. Data are shown for a semiconductor-type hydrogen sensor based on these thin films.