Abstract: [Problem to be Solved] When a wood raw material is heat-pressed in order to produce a woody material or woody board, steam is generated in an interior of the wood raw material. The heat-pressed wood raw material is then decompressed with the steam staying in the interior of the wood raw material. This causes a puncture or a rupture of the woody material. The puncture occurs in the last phase of the production process, thus spoiling the entire production process. In order to avoid the puncture, the wood raw material needs to be dried completely. This requires a large amount of energy.