Method for manufacturing a fiber material profile product of a fiber material, such as wood fiber, in which method in the board machine (1) the fiber pulp is led from the headbox (2) to the wire section (3), and in which water is removed from the pulp suspension and after the water extraction the pulp suspension (6) is detached from the wire (3) by means of a suction and detachment roll (4) and led to the press section (5), in which the pulp suspension is dried by means of drying elements, such as press rolls (7) and a felt (8), and in that a slitter (9) is disposed after the press section (5), in which slitter the pulp suspension is cut into webs and after which the webs (11) are led to a shaping and drying cylinder section (12), in which the webs are shaped, and in that one or more creases and/or round shapes are formed in the webs by folding and/or by creasing them in the longitudinal direction of the web in two or more consecutive phases in order to reduce breakage of the fibers, by means of shaping elements, such as cylinders (13,14) into fiber material profiles (15) of the desired shape and are led to the shearing cutter (16) for cutting.