SnO2 nanoparticles were synthesized by flame spray pyrolysis, which were directly deposited on Pt interdigitated substrates. Gas sensing performance was evaluated for various gases such as H2, CO, H2S, and NH3, and it was compared with that of commercial SnO2 nanopowder. The synthesis of SnO2 nanoparticles was also conducted in various solvents. As a result, the primary particle size was changed with the solvent of precursor solution, and their H2 sensing properties were significantly affected.