An integrated microchannel methanol processor was developed by assembling unit reactors, which were fabricated by stacking and bonding microchannel patterned stainless steel plates, including fuel vaporizer, heat exchanger, catalytic combustor and steam reformer. Commercially available Cu/ZnO/Al2O3 catalyst was coated inside the microchannel of the unit reactor for steam reforming. Pt/Al2O3 pellets prepared by 'incipient wetness' were filled in the cavity reactor for catalytic combustion. Those unit reactors were integrated to develop the fuel processor and operated at different reaction conditions to optimize the reactor performance, including methanol steam reformer and methanol catalytic combustor. The optimized fuel processor has the dimensions of 60 turn x 40 mm x 30 rum, and produced 450sccm reformed gas containing 73.3% H-2, 24.5% CO2 and 2.2% CO at 230-260 degrees C which can produce power output of 59 Wt. (c) 2005 Elsevier B.V. All rights reserved.