We prepared a new Rh/one-atomic-layer GeO2/SiO2 Catalyst by supporting Rh-6(CO)(16) precursor on the one-atomic-layer GeO2/SiO2. The obtained catalyst was active for conversion of ethyl acetate to ethanol by H-2 reduction under mild reaction conditions, Three different structures and chemical states of Rh species on the one-atomic-layer GeO2/SiO2, characterized by EXAFS, TPD, TEM, and FT-IR, were formed depending on the prereduction temperature, Rh carbonyl cluster, Rh metal, and RhGe alloy. The Rh atoms in the metallic stare were most active for the ethanol formation, The one-atomic-layer GeO2 was much more effective as support for the Rh metallic particles than three-dimensional GeO2-particles dispersed on SiO2. Rh/bulk-GeO2 and Rh/SiO2 were inactive for this reaction. Ethyl acetate dissociatively adsorbed on the one-atomic-layer GeO2, while hydrogen adsorbed on the Rh metallic particles. The present study exemplifies the advantageous applications of an inorganic oxide monolayer to preparation of supported metal catalysts.