PURPOSE: To enable mass production and to drastically reduce an assembly cost as well as to improve reliability by alternately juxtaposing through-holes and non-through- holes on two sets insulating supports of an ozone generator and inserting main cathodes and counter cathodes therein.

CONSTITUTION: In the ozone generator alternately juxtaposing the main cathodes and the counter cathodes, the through-holes and non-through-holes are alternately arranged in two sets of the insulating bases for supporting and fixing these cathodes. The main cathodes and counter cathodes are inserted into these holes and the cathodes of which head parts are exposed through the through-holes by each of the insulating supports are integrally electrically connected to juxtapose the main cathode group and the counter cathode group, by which the electricity collecting structure is formed. The insulating supports 1 shown in Fig. are disposed and fixed by an anode 2 and are disposed alternately with the through-holes 3 and the non-through-holes 4. The supports 1-1 and 1-2 are deviated by 0.5B and are disposed on one straight line. The other end houses in the opposite non-through-hole of 1-2 and one end heads in the through-hole of 1-1 when this cathode assembly is inserted through the through-hole from the left side of 1-1. The main cathode is thus constituted. The counter cathode is constituted by making the similar operation from the right side of 1-2.