To provide a garbage drier whose deodorizing effect is enhanced with small power consumption, and to provide a garbage drying method and a garbage drying agent.

Garbage is dried by mixing it with a drying agent containing at least ash, charcoal or lime in the garbage while heating the garbage and agitating the mixture. This garbage drier is constituted of an inner vessel for housing and heating the garbage, an outer vessel for housing the inner vessel and an agitation blade for agitating the garbage in the inner vessel. The garbage drying agent containing at least ash. powder or small pieces of charcoal or lime is mixed in the garbage for drying the garbage.