A glass multi-layered microreactor with a methanol reformer that could provide power to portable electronic devices was developed to supply hydrogen to a small proton exchange membrane fuel cell (PEMFC). The microreactor consisted of four units: a methanol reformer with a catalytic combustor, a CO remover and two vaporizers. The dimensions of the microreactor were estimated by thermal simulation in order to achieve the required reaction temperature of each unit. In this study, the glass multi-layered microreactor was produced using anodic bonding. The number of glass pieces of which the microreactor was composed was 13. The experimental temperature of each unit, as well as the heat loss, for a methanol reformer of temperatures at 280 degrees C was measured and compared with the results from thermal simulation. (c) 2005 Elsevier B.V. All rights reserved.