Gas sensors were designed and fabricated using oxide nanofibers as the sensing materials on micro platforms using micromachining technology. Pure and Pt doped SnO2 nanofibers were prepared by electrospinning and their H2S gas sensing characteristics were subsequently investigated. The sensing temperatures of 300 and 500 degrees C could be attained at the heater powers of 36 and 94 mW, respectively, and the sensors showed high and fast responses to H2S. The responses of 0.08 wt% Pt doped SnO2 nanofibers to 4-20 ppm H2S, were 25.9-40.6 times higher than those of pure SnO2 nanofibers. The gas sensing characteristics were discussed in relation to the catalytic promotion effect of Pt, nano-scale morphology of electrospun nanofibers, and sensor platform using micro heater. (C) 2011 Elsevier B.V. All rights reserved.