The multichannel potentiostat comprises a reference terminal, a counter-electrode terminal, and at least two working terminals, respectively designed to be connected to a reference electrode, a counter-electrode and at least two working electrodes of an electrochemical cell. The potentiostat comprises first and second regulating circuits to apply a setpoint voltage respectively between the first and second working terminals and the reference terminal. The potentiostat comprises a control circuit of the counter-electrode voltage applied to the counter-electrode terminal. The control circuit comprises a first input terminal connected to a predefined potential and a second input terminal to which a regulating voltage representative of at least one of the voltages of the working terminals is applied.