A press-molding device (80) press molds a bottom portion of a work piece (9) having a closed-end shape between an, inner die (521) inserted into the work piece (9) and an outer die (551) disposed on an outside of the work piece (9). A chuck position switching mechanism (501) grips the work piece (9) so that the work piece (9) can move in an axial direction. An inner die moving mechanism (522) inserts the inner die (521) into the inside end of the work piece (9). A stopper mechanism (531) supports the inner die (521) in a processing position by restricting movement of the inner die (521). An outer die moving mechanism (552) press-molds the bottom portion of the work piece (9) between the outer die (551) and the inner die (521), thereby press-molding the workpiece (9) smoothly without damaging an inner peripheral surface of the workpiece (9).