To constantly display actions such as aromatizing, insecticidal, antibacterial and deodorizing and a humidity control action by moisture absorption and desorption by fitting a wood for fitting of an irregular shape and containing a wood oil component, in a freely attachable/detachable manner, as a support part to the inner wall substrate of a storage shed, when projecting parts are firmly fitted.

A groove-like rail 9 is fitted to the inner wall 3 substrate of a storage shed 1 using a fixture such as screws, nails or an adhesive, and a foam 10 of a closed cell type is attached to the surroundings of the groove-like rail 9. Further, a wood 2 for fitting, with a first and a second surface of an irregular shape consisting of identical recessed and projecting parts 4, 5, which contains a wood oil component, is fitted, in a freely attachable/detachable manner, as a support part 6 in the groove- like rail 9, when the projecting parts 5 are firmly fitted. Thus it is possible to constantly display actions such as aromatizing, insecticidal, antibacterial and deodorizing and a humidity control action by moisture absorption and desorption with beneficial effects by volatilization of the wood oil component from the wood 2 for fitting exposed on the inward side of the storage shed 1.