The investigation of electrode processes calls for the use of methods that yield information on the reaction mechanism and the reaction rate, on the nature and stability of intermediates, and on adsorption processes at the electrode. It is no longer enough to record current-voltage curves or charging curves. In addition to the potentiostatic scan method, other methods that have proved useful for the investigation of electrode kinetics are the rotating disc electrode in particular, and to a smaller extent AC polarography. Intermediates can be identified with rotating double electrodes and by ESR spectroscopy or mass spectrometry. Adsorption processes on electrode surfaces can be studied by optical methods or by radioactive tracer methods.