PURPOSE: To improve productivity, while gluing strength is heightened and the positioning of mutual members is carried out easily and surely in manufacture by gluing, integrally wooden intermediate members to the platelike members on both side with depressions and protrusions.

CONSTITUTION: Laminated wood M1 is composed of two wooden plate members 1a having rectangular cross section and same width, and the wooden intermediate members 2a made of two small rectangular lumbers intervening between the plate members. On the opposite surfaces of both plate members 1a, the grooves 3a having three cross sectional inverse trapezoid are respectively engraved in parallel longitudinally at two positions of both sides. On the upper and lower surfaces of both intermediate members 2a, three ridges 3b having the cross sectional trapezoids corresponding to the grooves 3a are longitudinally formed in parallel respectively. These ridges 3b are set in the state of such a size, shape and arrangement interval that they may be inserted sufficiently into the corresponding grooves 3a. The grooves 3a and the ridges 3b are set in such dimensions that small gaps are formed for retaining the adhesive correspondingly to the properties of viscosity or impregnation and for discharging its excess amount.