The characteristics of a new-type of ozone-generating electrode with a catalyst layer fabricated by thermal decomposition were investigated. The catalyst layer consisted of insulating tantalum oxide and metallic platinum. Ozone generation was observed when the concentration of Ta of the catalyst layer was 70% and above and the maximum current efficiency of ozone generation was 6%. Scanning electron microscopy revealed cracks, which were capable of ozone generation, reaching the Pt buffered layer of the electrode. It is concluded that the cracks were the paths of the electrolyte and that electronic transfer was accomplished on the surface of the buffered layer. © 2005 The Electrochemical Society. All rights reserved.