The advantages of a new electrochemical cell for in situ UV-visible spectroscopy are presented using lithographic-galvanic microstructured metal foils (LIGA structures) as working electrodes to study electrochemical reaction mechanisms in aqueous and organic solvents under inert conditions. The properties (sensitivity, response time, conversion time) of this new type of spectroelectrochemical cell are determined with model redox systems in organic electrolytes. Furthermore, the calculation of the charge-time curves for the use of LIGA structures as a working electrode in a capillary slit is treated. The experimental results are compared with calculated curves as well as with the response behaviour of capillary slit cells with planar electrodes. The fast response time of the LIGA cell permits the study of fast chemical follow-up reactions and mechanistic investigations of more complex electrochemical reactions.