PROBLEM TO BE SOLVED: To provide a novel production method of laminate lumber capable of avoiding an adhesion failure phenomenon in a laminate lumber production step in a working environment at high temperature such as in a summer season.SOLUTION: The laminate lumber production method comprises: an adhesive application step for applying an aqueous adhesive to a lamina surface for forming an adhesive surface; a spray step for evenly spraying a constant amount of aqueous mist which has fine particle diameter per a surface area of the adhesive surface for making the adhesive surface wet; a lamina lamination step for laminating other lamina to which the aqueous adhesive has not been applied yet to the wet adhesive surface for forming a lamina laminate; and a tightening step for tightening the lamina laminate at room temperature.
