In this study, for the first time, we report the gas sensing behavior of aerogel-derived silicon oxycarbide (SiOC) glasses. The SiOC glass pyrolyzed at 1400 degrees C has specific surface area of 150m(2)/g with pore size in the 2-20nm range. SiOC sensor shows good response to 5ppm NO2 at 300 degrees C. NO2 response completely disappears at 400 degrees C, and from this temperature SiOC sensor starts respond to H-2. The optimum sensitivity for H-2 is obtained at 500 degrees C. SiOC sensor is very selective; it is not sensitive to other gases such as acetone vapor or CO, even at high concentrations.