The supply of heat to endothermic reactions through combustion reactions is the most direct and effective strategy for facilitating such reactions. The catalytic combustion of methanol at room temperature can provide broader applications of technologies that involve heat demand for chemical reactions. Hydrogen production from methanol steam reforming is a practical example. In recent years, the miniaturization of designs has become an inevitable trend due to advances in micro-electro-mechanical systems (MEMSs) technology. The micro-channel reactors prepared using MEMS technology may be a good choice for practical applications. The integration of exothermic and endothermic reactions may provide an advantage in micro-channel bed reactors. However, the progress of catalytic reactions in micro-channel reactors is not easily investigated. In this study, we designed a micro-channel reactor with a monitoring window that allowed images of fog and flames generated during the catalytic combustion of methanol. These images may advance the study of catalytic combustion on micro-channel plates. The results revealed that the configuration of the micro-channel plates affects the flow field of reactants. The catalytic activity of the catalysts also affects the gas flow field. The poor design of micro-channel configurations, which may result in a decrease in the utilization of the reaction bed area or instability of the flow field, should be avoided. The developed method provides a simple method for monitoring the practical flow field of combustion reactions in micro-channel reactors. (C) 2013 Elsevier B.V. All rights reserved.