An ozone purifying apparatus, for example as shown in Figure 1, comprises a float 18 which is arranged to float in polluted water 2 and which includes an ozone reaction region 25 in which the polluted water 2 is mixed with ozonide air for the purpose of carrying out an ozone processing on the polluted water 2 and an oxidant removing region 31 in which oxidant generated due to a reaction between the polluted water 2 and the ozonide air in the ozone reaction region 25 is removed. The ozone purifying apparatus does not occupy a wide space. Water levels in the float can be easily adjusted. Furthermore, the ozone purifying apparatus can be easily installed.
