Abstract: This invention relates to an ozonizer for generating ozone by causing a corona discharge to occur between electrodes oppositely arranged in air. An object of the ozonizer is to make the whole device compact and maintenance simple with reduction of the number of accessories. To this end, the ozonizer is characterized by that one of the electrodes comprises blades, the other electrode comprises a casing, and the blades and the casing form a blower. With this arrangement, it is not necessary to provide a particular blower for supplying fresh air continuously to the field of corona discharge and taking out ozone as it is produced.