PURPOSE: To obtain a sheet like material for adjusting humidity rapid in a speed response to the variation of humidity and low in temporary variation of humidity and the difference of equilibrium humidity, by uniformly bonding a powdery humidity adjusting agent and a fiber good in the humidity response to form an integral structure.

CONSTITUTION: An aqueous solution containing a powdery humidity adjusting agent such as modified montmorillonite clay is uniformly coated to Japanese paper and thin leaf paper is adhered thereon and dried to form a humidity adjusting sheet as powder coated paper or the powdery humidity adjusting agent is added to beaten kraft pulp and the resulting mixture is formed into a sheet by a papermaking method and dried to obtain the humidity adjusting sheet as powder mixed paper. This sheet is molded into a strip like shape or a plate like shape to be used in the structural member such as a case for cultural assets, a packing material for transportation of cultural assets, a building material or an interior material.