To provide a treating method for incineration ash capable of recycling granular materials in the incineration ash by efficiently making the granular materials non-polluting, and to provide aging facilities capable of efficiently and stably preventing the elution of heavy metals.

The incineration ash is fed into frictional crushing treatment devices 30 and 50 where the granular materials are made into finer grains by adding water thereto and acting the force to rub the granular materials against each other thereon and the fine grain components containing hazardous materials, such as heavy metals and dioxins, at high ratios are separated from the surface of the granular materials and thereafter the fine-grain incombustibles in the incineration ash are extracted by a vibration screen 60. These incombustibles are supplied to the aging facilities 80 where carbon dioxide is supplied thereto while a proper volume of water is added to the granular materials to bring the granular materials into contact with the carbon dioxide.