A monomolecular layer containing pyrrolyl groups at the surface was prepared between two parallel Pt electrodes on a glass substrate by a chemical adsorption technique using N-[11-(trichlorosilyl)undecyl]pyrrole. Then the pyrTolyl were polymerized inpure water by applying a 40-V DC between the two electrodes. It has been confirmed that several electric paths were formed between the two Pt electrodes by a decoration technique using electrochemical polymerization in an aqueous medium containing pyrrole after the polymerization. The resistance of the electric paths in the monomolecular layer has been measured using an atomic force microscope (AFM) attached with an Au-covered tip at room temperature. For a measurement volume of about 2 nm (thickness of the monomolecular layer) x 100 mum (the average width of an electric path) x 0.6 mm (the distance between Pt positive electrode and the Au-covered AFM tip) the resistance at room temperature of the electric path was 4 kOmega both under ambient conditions and in a reduced pressure of 1.2 x 10(-2) Pa. (C) 2004 Elsevier B.V. All fights reserved.