PURPOSE: To uniform the temperature in an ozone degradation column, prevent active carbon from getting deteriorated because of local heating and prevent ozone degradation performance from getting lowered because of local deterioration by providing a heat transfer material to transfer the heat to an outer periphery of a column in a central section of the ozone degradation column constituted of an active carbon layer.

CONSTITUTION: A heat transfer material 4 constituted of a stainless material with ozone oxidation resistance or the like is provided horizontally in the middle of an active carbon layer 5 of an ozone degradation column 1 to decompose the ozone in gas. The heat transfer material 4 can act as a diffusion plate for the gas flow in a central section of an ozone degradation column and also can uniform the heat of the active carbon layer in order to transfer and diffuse the heat to an outer periphery, which uniforms the consumption of active carbon and eliminates sinter consumption of active carbon generated by oxygen and offer an economical way of consumption.