A method for manufacturing a board product made up of at least two layers, and a multilayer board product. According to the method, the board webs (4, 5, 6) forming the layers are bonded together by gluing. According to the invention, at least one of the webs is treated mechanically by compression so that in the web surface there form permanent deformations projecting from the web surface, and the layers are glued together by using a starch-based adhesive, which is applied at a solids content over 45% to the layers to be bonded. The adhesive having a high solids content dries and bonds rapidly to the surfaces to be joined, even without additional heating. Since the adhesive contains little or no water, no after-bending or flattening of the middle layer occurs in the bond.