PURPOSE: To accurately and beautifully cut timber by providing a plurality of saw guiding fine grooves to timber so as to easily cut the timber in the longitudinal direction thereof and selecting the appropriate groove to saw the timber along the groove.

CONSTITUTION: V-shape fine grooves 12 are provided to the part between the timbers 1, 2 of laminated wood obtained by bonding timbers 1, 2, 3 by an adhesive along the longitudinal direction of the laminated wood and a V-shape groove 23 is provided to the part between the timbers 2, 3 of the laminated wood along the longitudinal direction thereof. Therefore, when a saw 5 is operated along the groove, the timbers 1, 2 are cut and separated and, when the saw 5 is operated along the groove 23, the timbers 2, 3 are cut and separated. Therefore, the timbers 1, 2, 3 can be easily, accurately and beautifully cut along the longitudinal direction of the laminated wood.