Microchannel reactor offers opportunities for the development of compact fuel processor for PEMFCs. The design and experimental work concerning a microdevice for the methane steam reforming with hydrogen catalytic combustion is presented herein. We designed novel flow channel on reformer sheets and microholes on combustor sheet to inhibit the hot spot, which takes place in front of the reactor. Experimental results show that the Pt-Sn/Al2O3 coated microchannel combustor was active enough to initiate hydrogen combustion at room temperature and able to increase reactor temperature up to 800 degrees C by hydrogen combustion uniformly. The performance of the microchannel reformer was investigated at various operating conditions. The developed micro fuel processor generates enough hydrogen for power output of 26 W as fuel cell. (c) 2005 Elsevier B.V. All rights reserved.