Chemiresistive gas sensing properties of Fe₂O₃ thin films have been investigated. The sensor films were prepared by oxidation of Fe films, deposited by electron-beam evaporation method on sapphire substrates. We demonstrate that these films exhibit reversible response towards H₂S in the concentration range of 1–50 ppm, with fast response and recovery times. Modification of these films by Au resulted in the enhancement of response towards H₂S. Au, as a sensitizer helps in improving the sensors response by a spill-over effect.