Methanol was decomposed to carbon monoxide and hydrogen on supported precious metals. Among the precious metals examined the performance of Pt was found to be the best, and ceria was the best support. Pt/CeO2 decomposed methanol completely at 230 degrees C with 99.2% and 94.6% of selectivities to H-2 and CO, respectively TEM, ESCA, and XAFS analyses showed that Pt interacted very strongly with ceria, indicating the possibility of the formation of Pt-O-Ce bond and the penetration of Pt into the bulk ceria. The reaction mechanism was discussed on the basis of the kinetic analysis.