To provide a manufacturing method of laminated lumbers which is free from causing wrinkles by press forming.

In a lamination process, five or more thin wooden sheets are laminated into a layer structure and unified by an adhesive. In this process, lamination is performed so that grain directions of two or more of lower thin wooden sheets 1 and two or more of upper thin wooden sheets 1 are the same, and that a grain direction of one thin wooden sheet 2 in the middle is approximately orthogonal to those of the upper and lower thin wooden sheets.