This article describes the design, fabrication and initial testing of an enzymatic microreactor using Si, glass, epoxy and Perspex components. The microreactor geometry was defined by a photostructured EPON SU-8 spacer. This gave two chambers, an upstream chamber (vol. 2.7 l) which was packed with control pore glass (CPG) and a downstream chamber (vol. 1.5 l) which contained the detectors. Eleven EPON SU-8 columns separated the chambers and prevented the CPG from passing. Glucose detection via glucose oxidase immobilized to the CPG was used as a model system. Conversion efficiencies between 15 and 60% at flow rates of 150 and 26 1 min^–1 respectively were obtained. Overall the system was found to be robust and to have a lifetime of at least one month.