To provide a disposer apparatus for decomposing garbage without exerting a bad influence on the environment.

This disposer apparatus 1 is provided with: a crushing chamber 2 for crushing the garbage thrown from a sinkhole of a sink in a slurry state and; a decomposing chamber 3 arranged under the crushing chamber 2 for perfectly decomposing the crushed garbage 18 of a slurry state by supercritical or subcritical water. In other word, this disposer apparatus 1 realizes perfect decomposition of garbage by a catalytic reaction of crushed garbage with supercritical or subcritical water. Garbage can be decomposed by using this disposer apparatus to the extent that the decomposed garbage satisfies a water quality standard sufficiently and is made to flow in a sewer in Japan.