The SO2-sensitive organic silicate film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 0.1 kHz

1 kHz and 10 kHz. It was shown that there was a linear relationship between the capacitance and the concentration of sulfur dioxide gas. The influences of the measurement frequency and the film thickness of silicate on the sensitivity of the sensor to SO2 gas were discussed.Organically modified N

N-diethylaminopropyltrimethoxysilane showed a much higher sensitivity.