An ozone generator is provided with a pulse generator (110) that at least includes pulse generation means for generating a pulse voltage and a magnetic switch (SI2) adjusting pulse width of the generated pulse voltage, and a discharge reactor that is provided with a plurality of electrodes to which the pulse voltage for which the pulse width has been adjusted is applied, and that generates a discharge between the plurality of electrodes as a result of the pulse voltage, for which the pulse width has been adjusted, being applied thereto, and also generates ozone as a result of a raw material gas containing oxygen being supplied from the outside to between the electrodes where the discharge has been generated.