FIELD: heat engineering. SUBSTANCE: invention relates to a method and a device for the manufacture of a ribbed thin-sheet panel; it can be used in structures of recuperative heat exchangers. A ribbed thin-sheet panel is manufactured, which contains base (1) made of a metal sheet and metal ribs (2) welded to it. To weld ribs (2) to base (1), clamping device (3) is used, main working elements of which are support (4) and clamping (5) rails. Ribs are inserted into corresponding grooves of the device. Using a system of eccentric clamps or using screws, clamping rails (5) are tightened, thereby rigidly fixing ribs (2) in the space. A sheet base is mounted, rigidly fixed on one side, and inserted into movable clamps (6) on the other side. The sheet base is tightened. Using CNC machine, ribs (2) are welded to the base through sheet base (1) according to a set program. EFFECT: invention simplifies the manufacture of large-size flat thin-sheet ribbed panels with sheet ribs, allows for reduction in material consumption of a product and decrease in spoilage in the manufacture. 10 cl, 5 dwg.