Abstract: The invention illustrates a method for producing mixed electrolyzed water of cathode-side electrolyzed water and anode-side electrolyzed water by supplying an aqueous electrolytic solution that contains a chloride salt and an inorganic acid to a non-diaphragm electrolytic cell that has at least a pair of inert electrodes having an electrode-to-electrode distance of at most 2 mm, and electrolyzing it, which is characterized in that the polarity of the electric power to be supplied between at least the pair of inert electrodes is alternated at least 2 times or more per minute.