The study is the first step in a design of an electrochemical reactor able to process enzyme catalysed electrochemical synthesis. To develop economically efficient synthesis, the enzymes must be confined very close to the electrode surface. Here, the confinement was achieved with a dialysis membrane integrated in a classic filter-press electrochemical reactor. A simple electrochemical reaction, without enzymatic catalysis, was used to model the behaviour of the 'dialysis membrane electrochemical reactor' (D-MER). The values of the physicochemical parameters were determined by independent experiments, and the thickness of the reaction layer in the reactor was the only parameter to be adjusted numerically. The conditions of this adjustment were discussed. The model gave a good fit to the experimental data and consequently proved that the current design of the reactor is ready to be used with more complex reactions as enzymatic synthesis. A first example was described, based on the glucose oxidase-catalysed synthesis of gluconic acid.