Abstract: The present invention relates to a device for reducing the pressure and velocity of a flowing fluid. According to the present invention, a cage has discs having through holes which come into close contact with an outer surface of a plug. The discs are stacked in a direction of a central shaft of the cage. Flow passage portions are formed on the stacked discs, wherein the flow passage portions communicate with the outer surfaces of the discs, and the inner surfaces which correspond to the through-holes so as to form flow passages between the stacked discs, and the direction of the flow passages changes to a circumferential direction and a vertical direction on the stacked discs.