To provide a wood drying method which is suitable for the time-saving natural drying process by simply pretreating the surface of the wood and can inhibit damage e.g. cracking, even in case the moisture content as a crack generating point indicator is reduced beyond the conventional limits and can be applied to an artificial drying.

In the natural drying of the wood as a core material with the center of annual growth rings of tree found in the central part of a square section, longitudinal fine grooves are nicked in the surface of the wood along a position for previously dividing the width of each side of the wood into three equal parts or almost three equal parts. Thus, the very simple surface treatment is performed by nicking the two fine groove from the aesthetic predistribution of three equal parts to each side. Consequently, the drying time can be cut and the utilization efficiency of a field stacking area be improved in the natural drying. Besides, no damage such as cracks occurs, even in case the moisture content as the crack generating point indicator, is reduced beyond the conventional limits. For the above reasons, this method contributes to the use of the wood as a finished product e.g. a beam or a girder without resorting to the costly artificial drying and also, is the best-suited choice for the artificial drying.