To accelerate the heating up when garbage, etc., corrode and to efficiently produce compost by using cylindrical chips formed by slicing and curling timber so as to face diagonal with the pith as a moisture control agent when the compost is produced by incorporating the moisture control agent into the garbage, etc.

The moisture control agent is formed from the cylindrical chips 1 formed by slicing and curling the timber so as to face diagonal with the pith. The compost is produced by incorporating the moisture control agent consisting of the many chips 1 into the garbage, agricultural residues, domestic animal dung, etc. As a result, the contact of air with the garbage, etc., is improved by the curling parts of the chips 1 and maturing is improved by the pressing force, etc., of an operator. Then, the heating up when the garbage, etc., corrode may be accelerated and drying may be sufficiently executed and, therefore, the good-quality compost may be efficiently produced.