A TUBULAR-SHAPED OZONIZER OF THE TYPE EQUIPPED WITH A COOLED INNER ELECTRODE AND A DIELECTRIC TUBE CONCENTRICALLY ARRANGED BETWEEN THE INNER ELECTRODE AND AN OUTER ELECTRODE. THE TUBULAR-SHAPED INNER AND OUTER ELECTRODES AND THE DIELECTRIC ELECTRODE ARE HELD AND MAINTAINED IN SPACED RELATIONSHIP FROM ONE ANOTHER BY ELECTRICALLY INSULATING CLOSURE CAP MEMBERS MOUNTED AT THEIR ENDS. ACCORDING TO THE INVENTION, THE SPACE BETWEEN THE INNER ELECTRODE AND THE OUTER ELECTRODE WHICH IS OF SUBSTANTIALLY CIRCULAR-SHAPED CROSS-SECTIONAL CONFIGURATION IS SUBDIVIDED BY THE DIELECTRIC TUBE INTO AN OUTER DISCHARGE

COMPARTMENT AND AN INNER COOLING COMPARTMENT. THE DISCHARGE COMPARTMENT AND COOLING COMPARTMENT COMMUNICATE BY MEANS OF SPACED HOLLOW COMPARTMENTS OF THE CLOSURE CAPS WITH CONDUIT CONNECTIONS PROVIDED AT SUCH CLOSURE CAPS FOR SUPPLYING THE DISCHARGE COMPARTMENT WITH AIR AND THE COOLING COMPARTMENT WITH A COOLING FLUID MEDIUM.