Abstract: A device for in situ foaming and/or injection molding an essentially plate-shaped workpiece (14), especially a transparent cover element of a vehicle roof, has a tool unit (10) with an upper tool (18) and a lower tool (20) which, together, form a mold cavity (22) for forming a frame in the area of the edge of the workpiece (14). The tool unit (10) encloses at least one elastically deformable shaped gasket (30) which, with the tool unit (10) closed, adjoins the edge surface of the workpiece (14) in an area adjoining a recessed region of the frame, so that the workpiece (14) is free of foamed or injection molded material adjoining the recessed region after the process of in situ foaming or injecting has been completed.