<p>There is disclosed an ozone decomposing reactor element which comprises a catalyst structure 10 composed of a carrier having at least one passage 11 extending therethrough for allowing an ozone containing fluid to pass through the catalyst structure and catalyst and electroconductive material carried in or on the carrier; and electrodes 12 attached to the catalyst structure for electrifying the structure to decompose ozone at elevated temperature. The carrier is either a ceramic honeycomb mold or of fiber board.</p>
