To deodorize not only formalin odors but also environmental bad smells from a particle board itself by blending activated charcoal in a particle board with wood pieces applied with a thermosetting synthetic resin agent thermally compressed into a board.

For wood pieces, there is used a woody waste material and so forth fractured into chips. In this case when a thermosetting synthetic resin adhesive such as ureaformaldehyde resin for an adhesive in convention is employed, activated charcoal blended in the particle board absorbs formalin developed. Also, even in the case when an adhesive not developing bed smells in such a thermosetting synthetic resin adhesive is used, activated charcoal blended absorbs and deodorizes bad smells in an environment of the particle board. Particularly, though the blending quantity of activated charcoal is 3-15wt.% with respect to 100wt.% thermosetting synthetic resin adhesive to be applied, this is because when the application quantity of activated charcoal exceeds 15wt.%, the bending strength becomes low, and when less than 3wt.%, a remarkable effect can not be expected.