A series of SrFeyCozOx thin films on sapphire substrates was prepared by laser deposition and the conductance responses to both temperature and gas composition in O-2/N-2 mixtures were examined. All films exhibited p-type semiconductor behavior with film conductivities at 500degreesC between 20 and 200 S/cm for films exposed to 100% O-2 atm and 0.4-25 S/cm for films exposed to 0.2% O-2. At 500degreesC, thin films of compositions SrFeyCo1-yOx, 0.25less than or equal toyless than or equal to0.75, were found to be the most conductive for oxygen partial pressures between 0.002, p(O 2), 1.0 atm. SrFeOx and SrFe1.3Co0.2Ox films were found to be the least conductive under these conditions. SrFe0.25Co0.75Ox and SrFe0.5Co0.5Ox films were found to exhibit regions where conductivity exhibited temperature independence between 200less than or equal toTless than or equal to500degreesC for oxygen concentrations between 0.2 and 100% O-2. The temperature independence was interpreted as the result of a balancing of two opposing thermal effects: thermal activation of charge carriers and thermal-induced oxygen stoichiometry changes. For some films, enhanced oxygen sensitivity was observed over narrow p(O 2) regions, and is attributed to cubic perovskite to brownmillerite phase transitions. CO and H-2 gases could be detected in background air for conditions where there is negligible temperature dependence of conduction.