A skinned panel for stably molding a thin skin material and a molding method thereof. An extruding device is configured to extrude a pair of multilayered resin sheets, each of which has a lamination structure of an inner layer made of a foamed resin and an outer layer made of a non-foamed resin that is changed into a skin material of a sandwich panel as a skinned panel. The pair of the resin sheets is abutted to the circumferential part of the pair of the split molds for producing sealed spaces. The sealed spaces are sucked for pressing the pair of the resin sheets onto cavities of the pair of the split molds. Accordingly, the pair of the resin sheets is formed in a shape substantially identical to the outline of the sandwich panel.