To facilitate installation without needing special work to attach a deodorizing device and without needing instllation work by constituting a structure so that a separately provided deodorizing device can be fitted to a discharge duct outlet of a casing bottom part.

A discharge duct outlet 23 is constituted, if necessary, below a casing 'a' so that a deodorizing device B separately provided is fitted to the casing 'a', put under it. The deodorizing device B fitted to the casing 'a', put under it is formed into a square deodorizing box body 'b' and four corners on an upper side plate 24 thereof can be provided with supporting legs 14 of the casing 'a'. Therefore, with the casing 'a' being laid on a deodorizing box body 'b', the discharge duct outlet 23 is made to communicate with and provided successively to the deodorizing device B. When attaching the deodorizing device B to a garbage disposal device A, the deodorizing device B is arranged, put under the casing 'a' in advance, and the discharge duct outlet 23 is made to communicate with a connecting cylinder 25 of the deodorizing device B, laid over the cylinder 25, thereby the garbage disposal device A and the deodorizing device B are incorporated into one body and made to communicate with each other.