An electrolyzer inc;ides a receptacle having a chamber and an inlet port for receiving an electrolytic solution, one or more cathode plates and one or more anode plates disposed alternatively in the receptacle and separated from each other for forming flowing passages between the cathode plates and the anode plates, the cathode plates may generate and attract anolyte toward the cathode plate, and the anode plates may generate and attract catholyte toward the anode plate The receptacle two separated compartments communicating with the chamber of the receptacle, and a guiding device may effectively guide the catholyte and the anolyte to flow into the two compartments of the receptacle respectively.