A through-chip porous Ru-Pt catalyst layer was fabricated on a Si wafer and a novel miniature DMFC( Direct Methanol Fuel Cell) was realized. Recently, we found that porous noble metal layer can be synthesized on Si substrate by immersion plating on a porous Si. In order to realize a DMFC with our novel structure, a porous Ru layer was synthesized on the Si substrate using the immersion plating on the porous Si, then Pt was deposited by galvanic replacement reaction on the porous Ru. The porous Ru-Pt structure showed catalytic activity on methanol oxidization. A through-chip porous Ru-Pt layer was fabricated on a Si wafer by plasma etching and monolithic electrodes with catalyst layers and fuel channels were realized. A preliminary DMFC prototype successfully demonstrated power generation of 2mW/cm2.