To reduce the capacity of an activated carbon type deodorizing unit, to control differential pressure of a refuse pit to prevent leakage of odor, to facilitate an operation of a hot stove for dryer or a deodorizing furnace, and to deodorize odor air as a combustion air of an incinerating furnace when the furnace is installed in parallel with an RDF manufacturing facility.

Odor air is collected from respective odor generating zones of an RDF manufacturing apparatus 1 to a refuse pit 2. Part of the collected odor air is sent from the pit 2 to a hot stove for a dryer or deodorizing furnace as combustion air. Simultaneously, its residue is sucked from the pit 2 by a deodorizing fan 6 through a deodorizing unit 5 so that the pit 2 is always held at a negative pressure. A differential pressure between the pit 2 and a platform 9 or the atmosphere is detected by a differential pressure gage 11, and an odor air amount is controlled so that the detected value falls within a predetermined range. Thus, the unit 5 is controlled to be operated.