A garbage disposal apparatus having a processing chamber for processing garbage; and a purifying chamber for purifying gas discharged from the processing chamber and containing stinking components, wherein the process of garbage in the processing chamber is performed by decomposition using microorganisms, the purifying chamber has a plurality of zones, a first purifying chamber connected to the processing chamber is provided with an ammonia purifying unit for purifying ammonia and a second purifying chamber into which gas allowed to pass through the first purifying chamber is introduced is provided with a non-ammonia purifying unit for purifying non-ammonia gas. Ammonia contained in a high concentration and having a large threshold is first removed in the first purifying chamber. Then, non-ammonia contained at a low concentration and having a small threshold is removed. Therefore, an excellent purifying efficiency can be realized.