Indium oxide nanostructures have been prepared by carbothermal reduction method. From them, nanowires have been structurally and optically characterized using X-ray diffraction, scanning and transmission electron microscopy and photoluminescence. The indium oxide nanowires have been removed from the substrate and contacted by Focused Electron- and Focused Ion-Beam Induced Deposition techniques to interdigitates on suspended microhotplates, which allow heating up to 300 °C with a low power consumption of only 8 mW. The gas response of the tested devices towards ethanol, carbon monoxide and nitrogen dioxide diluted in dry synthetic air at different concentrations and temperatures has been carried out showing a selectivity towards ethanol with responses up to 50% at temperatures between 200 and 300 °C, while only small response to high concentrations of carbon monoxide and nitrogen dioxide is observed. [ABSTRACT FROM AUTHOR]