Utilizing a fluid motion induced by electromagnetic force, a new method of voltammetry under forced convection was developed. The electrolytic cell was composed of two pairs of electrodes, viz., generator and detector pairs embedded on the bottom and top innerwalls of a rectangular channel. An intermediate produced on the surface of one of the first generator pair of the electrodes was swept downstream by the induced liquid flow to the neighboring electrode of the second detector pair and measured as a current. Examination of the mechanism between the induced flow of the electrolyte solution and the diffusion process of the intermediate permitted deriving the several expressions of electrolytic current for each pair of the electrodes as functions of bulk concentration of reacting species and externally applied magnetic field. It was also predicted that the detecting current interacts with the generating current, which can be depicted in terms of the collection efficiency of the intermediate. Observed results in experiments were in good agreement with these predictions.