The use of micro structured reactors is an accepted technology in fundamental chemical research as well as in industrial applications. The application of electrochemical microreactors (ECMR) has not attracted as much attention as continuously performed reactions in a confined space. Nevertheless ECMRs are in use to perform electro-organic reactions. In this review, different aspects of ECMRs with structured electrodes and interelectrode distances of mainly a parts per thousand currency sign100 mu m are investigated and discussed, together with various manufacturing techniques and prototypes described therein. Based on representative examples described in various publications for electrolysis (for direct and indirect electrolysis) advantages and disadvantages of electrochemical microreactors are presented and compared with those of conventional electrochemical reactors.