To produce a newly value-added useful substance by purposefully uniting the treatment of locally generated large amounts of woody wastes such as wood chips and saw dust, abundantly growing bamboo and excess hot spring water in some areas.

Woody wastes such as wood chips, saw dust, and the likes are burned and the heat generated by the combustion is utilized for bamboo charcoal production, concentration of hot spring water, or fumigation of raw refuse. Further, steam generated at the time of producing concentrated hot spring water may be utilized for electric power generation, if necessary. Wood ash, bamboo charcoal, bamboo pyroligneous acids, concentrated hot spring water, and/or fumigated raw refuse is thus produced. Useful substances can be produced by combustion of the woody wastes in such a manner.