To provide a wood board emitting a small amount of formaldehyde and having an excellent mildew resistance.

A wood board such as an intermediate duty fiber board, a particle board and the like is obtained by adding 3-iodine-2-propynyl butyl carbamate being an organic iodine based mildew-proofing agent to an adhesive emitting a small amount of formaldehyde, mixing the resulting adhesive with wood fiber or wood sliced sheet piece and forming the mixture by hot pressing. The board emits only a small amount of formaldehyde and has excellent mildew resistance.