A device for manufacturing a composite sheet (5) comprising at least one corrugated sheet (1) and at least one flat sheet (3), which is glued to the wave peaks of the corrugated sheet (1), said device comprising at least one fluted roller (13) for shaping and/or maintaining the shape of the corrugated sheet (1), said roller being covered with the corrugated sheet (1) around a portion of its circumference during operation, and a gluing unit (27) for applying a liquid glue used to attach the corrugated sheet (1) to the flat sheet (3), with said gluing unit (27) having a gluing roller (45) whose outer surface (47) is continuously coated with a glue film and whose axis is essentially parallel to that of the fluted roller (13), said gluing roller being driven at approximately the same peripheral speed as that of the fluted roller (13), and with it being possible, using means for moving the rollers closer together (53, 65, 67, 69), to move said gluing roller, with its outer surface (47) against the portion of the circumference of the fluted roller (13) which is covered with the corrugated sheet (1), into a close-up position forming a gluing gap that allows the glue to be transmitted to the wave peaks of the corrugated sheet (1). The means for moving the rollers closer together (53, 65, 67, 69) are designed so as to press the gluing roller (45) against the corrugated sheet (1) and the corrugated sheet (1) against the fluted roller (13). Because the gluing roller (45) is pressed against the corrugated sheet (1), positional measurements of the gluing gap, which are prone to error, are unnecessary. Moreover, a highly uniform gluing pattern of the wave peaks of the corrugated sheet (1) is maintained by providing means for adjusting and controlling the compressive force between the gluing roller (45) and the fluted roller (13).