A thin film was formed by spreading a chloroform dispersion of a hydrophobic clay-organic complex at an air-water interface. The clay-organic complexes were prepared by reacting synthetic saponite with 3-(aminopropyl)dimethylethoxysilane and thereafter with alkanoyl chlorides. From the analysis of surface pressure-area curves, it was concluded that the film were composed of 1-3 layers of clay crystallites. The film was repeatedly transferred onto a glassy carbon electrode to build up 30 layers by the Langmuir-Blodgett method. An electrode modified with the clay multilayer was found to be electroactive when it was soaked in an aqueous solution of [Ru(bpy)(3)]Cl-2 (1 x 10(-5) M) and Na2SO4 (0.05 M).