To effectively deodorize the malodor gas generated from wastes by passing the malodor gas through the first layer containing a deodorant such as silica having ferric sulfate as a complex component and the second layer containing the deodorant such as silica having an active metal oxide as the complex component in sequence.

A cartridge 8 is arranged between the inlet nozzle 6 and outlet nozzle 7 of this deodorizing device 5 provided on the exhaust duct of a compost facility. Three air-permeable partition walls 9 are fitted in the cartridge 8 to form two spaces 10, 11. The capacity ratio between the spaces 10, 11 is set to 1:1-1:3, silica 12 having ferric sulfate as a complex component is filled in the space 10, and silica 13 having an active metal oxide as the complex component is filled in the space 11. A porous carrier having ferric sulfate as the complex component and having the OH group can be used as an oxidation catalyst deodorant.