Molecular Coulomb islands for single-electron tunneling is SiO2/molecular layer/SiO2 multilayers on Si(100) Y.wakayama a) National Institute for Materials Science, Nanomaterials Laboratry, 2268-1 Shimoshidami, Moriyama-ku, Nagoya 463-0003, Japan T. Kubota, H. Suzuki, T. kamikado, and S. Mashiko Kansai Advanced Research Center, Communications Research Laboratory, 588-2 Iwaoka, Nishi-ku, Kobe651-2401, Japan Abstract We demonstrate the Coulomb blockade phenomenon by using organic molecules as Coulomb islands embedded in a metal-oxide-semiconductor structure, Staircases in current-voltage(I-V)curves are abserved in an SiO2/fullerene(C60)/SiO2 multilayered structure on Si(100) substrates. The staircases in the I-V curves can be attributed to the Coulomb blocade. The fullerenes serve as Coulomb a porphyrin derivative also exhibits similar staircases in an I-V curve. These results reveal the potential of molecules to act as Coulomb islands of single-electron tunneling devices.