To provide a raw material which is high in hazardous material absorptivity and unlikely to mold.

Rush raw materials configuring bundled raw materials are coated with persimmon tannin. The bundled raw materials are formed in a substantially circular column shape. Each of an upper end face and a lower end face of the bundled raw materials is formed by a plurality of sections CS of the rush raw materials. Moreover, the shape of the plurality of rush raw materials united into one is maintained in a bundled body by one or a plurality of rubber bands wound around them. The bundled raw materials are installed on a wall of a habitable room in an accommodated state in a space surrounded by a frame body 10 and a plate body 12 so that upper end surfaces thereof face the habitable room side.