Electrochemical Process have been used for decades in various industrial branches. Electrochemical techniques represent powerful tools for investigation for physical phenomena such as mass transfer or hydrodynamics in the vicinity of solid surface in contact with liquid. This book consists of six chapters. The first one explains etching process and the copper etching machine, the second and third chapters cover the electrochemical reactors, optimization, modeling and their uses with supporting by many literatures in the same field. Chapter four deals with the experimental work of an electrochemical cell and its efficiency for regeneration of copper etching solution. While chapter five discusses the results of these experiments and optimizing them by Box-Wilson method then represents it by the suitable new model. Finally, chapter six represent the highlight of the book wherein the previous chapters the performance, optimization and modeling of electrochemical reactor are applied for real industrial process.