Gas sensor was fabricated by dispersing SnO2 nanowires on an interdigitated Pt-electrode. H2 gas sensing properties of these sensors made of nanowires prepared on three different substrates were measured at various operating temperatures and concentrations respectively. SnO2 nanowires deposited on Au-coated substrates showed the highest sensitivity of 11.5 at 100 °C upon exposure to H2 gas of 1000 ppm.