Provided are: a device that is for separating/housing blood components and that can more easily and aseptically separate/house platelet-rich plasma; and a method for preparing platelet-rich plasma. The device (1) for separating/housing blood components is provided with: a blood storage section (2); a component housing section (3) for housing a component that is part of blood; and a linking tube (4) that joins the blood storage section (2) and the component housing section (3). The blood storage section (2) has: a tube-shaped blood storage vessel (21) that is flexible; a blood lead-in pathway (27) that leads blood into the blood storage vessel (21); and a component lead-out pathway (28) that leads out a component that is part of blood from the blood storage vessel (21). The component housing section (3) has: a component lead-in pathway (37) that leads in a component that is part of blood led out from the blood storage vessel (21); and a metal needle (371) that extends from the component lead-in pathway (37) to
