In this work, SnO2 thin films were deposited onto microspores glass substrate at 250°C by spray pyrolysis technique. The films were studied after annealing in air at temperatures 200°C, 250°C and 300°C for 15 min. These films were tested in HS gas at different operating temperatures ranging from 50-300°C. The film showed maximum sensitivity to HS gas. The effect of annealing temperature on the optical and gas sensing properties of the films were studied and discussed. It was found that the annealing temperature significantly affects the sensitivity of the SnO2 to the H2S. The sensitivity was found to be maximum for the film annealed at temperature 250°C. The quick response and fast recovery are the main features of this film.