PURPOSE: To enhance the producibility by slicing a conifer continuously, laminating the obtained veneers one over another and joining together with the fibers intersecting at right angles, preparing a matrix through mixing and kneading of in a die between the front and rear veneers, and consolidating them together through heating and pressurization.

CONSTITUTION: Veneers produced by slicing a conifer in the circumferential direction at the periphery are laminated one over another and joined together while the fibers are oriented as intersecting at right angles. As a heart wood 3, 60-220 parts by wt. vulcanized granular rubber of particle size ranging 1.0-3.0 mm, 60-90 parts by wt. butyl rubber, and low density polyethylene are mixed together and kneaded, to which 240-640 parts by wt. wood chips, a stickiness giving agent, etc., are added, followed by mixing thoroughly and kneading. Thus the matrix 3 is prepared. A denatured polyolefin having polar group is added to low density polyethylene to prepare adhesive plastic sheet 2. Then the matrix 3 is put in a die D between the front and rear veneers 1, 1 while such plastic sheets 2 are interposed, followed by heating and pressurization to yield a consolidated structure. Therein the content of the low density polyethylene shall be 10-40 parts by wt.