To provide a moisture conditioning material capable of effectively reutilizing combustion ash of wood pieces.

Diatomaceous earth is compounded with combustion ash of wood pieces, which is generated by burning wood pieces generated from a disassembling building site in an industrial boiler, as a porous inorganic binder in a predetermined ratio and a proper amount of water is added to the obtained compound to be kneaded therewith. After sufficient kneading, the kneaded mixture is granulated to be dried to obtain a granular moisture conditioning material. By this method, the moisture conditioning material utilizing combustion ash of wood pieces, excellent in moisture conditioning properties and handling properties can be manufactured. By making it possible to recycle combustion ash of wood pieces discarded heretofore, this method can contribute to the reduction of the disposal quantity of combustion ash and can become the solving measure of a final disposal plant being the present point at issue.