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.