To provide a method and apparatus for regenerating an absorbent of an adsorption tower which can be carried out efficient regeneration operation in regeneration of activated carbon with hot water in subcritial water state.

In a method for regenerating activated carbon in adsorption towers 10A, 10B filled with the activated carbon as an absorbent after lubricating oils dissolved in LPG or the like are removed by adsorption by passing the LPG through the adsorption towers 10A, 10B, regeneration is carried out by supplying hot water under a subcritical pressure to the adsorption towers 10A, 10B and at the time the hot water from the adsorption towers 10A, 10B is repeatedly circulated by a circulation means 1 for hot water under a subcritical pressure.