An electrolytic ozone generator comprising anode chamber 3 and cathode chamber 4 partitioned by solid electrolyte 2, in which deionized water is electrolyzed in the cathode chamber while feeding air or oxygen-rich air to the cathode chamber through, for example, air holes 14. The air fed suppresses evolution of hydrogen gas thereby affording a saving of energy and eliminating the need a separate cooling mechanism. Furthermore, the air also decomposes ozone having entered the catholyte.