The gas-sensing characteristics and the morphology of vanadium pentoxide thin films have been investigated. The thin films were prepared by reactive electron beam evaporation of vanadium on surface-oxidised silicon wafers and additional thermal oxidation. Structural and morphological analyses of the V2O5 thin films in the thickness range of 100–200nm were performed. The polycrystalline monophase V2O5 films consist of grains with surface areas in the range of 100 nm to 1 μm square. Gas measurements were carried out with single-chip thin-film sensor arrays in synthetic air with 50% humidity. The sensors are analytically suitable as they are sensitive to ammonia, methane, carbon monoxide and nitric dioxide. Particularly for NO2, a distinctive temperature dependence of the gas reaction has been observed.