The aim of this paper is to present the gas sensing performance of In 2 O 3 and Sn-doped In 2 O 3 films prepared by a novel technique, i.e., Electrostatic Spray Deposition technique. The morphology and the microstructure studies reveal that the films are porous comprising grains in the nanometer range and crystallizing in the cubic structure. The present films prove to be sensitive to low H 2 S concentrations (1–10ppm) at low operating temperature (200°C). Undoped films present a very high sensitivity to H 2 S, compared with doped films, and a negligible response to NO 2 and SO 2 . Sn dopant introduced in In 2 O 3 causes a great sensitivity decrease in H 2 S response, and, on the contrary, a slight increase in NO 2 and SO 2 response.