[en] Tin oxide is the main material utilized for the fabrication of chemical sensing pellets which operate at elevated temperatures. The heating is commonly carried out with ruthenium dioxide resistors. Here, a tin oxide-based microheater is developed for microsensor applications. These microheaters are fabricated on 0.5 mm thick alumina substrates using spray pyrolysis technique. The optimum SnO_2 heaters have a sheet resistivity in the 40-70 Ω/a range. Ohmic Ag/SnO_2 contacts are formed by silver paste printing followed by an appropriate thermal annealing, which provide connections to the external circuitry. Durability tests are carried out on several samples; the long-term performance of the fabricated devices is satisfactory. The method allows the elimination of the expensive ruthenium dioxide from the structure of generic gas sensors. (paper)