The cells used for electro-Fenton process look quite different, ranging from the simple open tanks, through the parallel-plate cells, to the sometimes complex designs with three-dimensional moving electrodes or microelectrodes. Recently, pressurized cells and microreactors have been used to improve the performance of the process. This chapter presents a general overview of the main cell configurations used in electro-Fenton process for the treatment of organic pollutants. A global perspective on the fundamentals and experimental setups is offered, and laboratory-scale and pilot-scale experiments are examined and discussed.