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 joining 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) towards the interior space of the component housing section (3) and can return the component that is part of blood housed in the component housing section (3) towards the blood storage vessel (21).L'invention concerne un dispositif qui est conçu pour séparer/recevoir des composants sanguins et qui peut séparer/recevoir plus facilement et de façon aseptique un plasma riche en plaquettes ； et un procédé de préparation de plasma riche en plaquettes. Le dispositif (1) pour séparer/recevoir des composants sanguins comporte : une section (2) de stockage de sang ； une section (3) de réception de composant pour recevoir un composant qui fait partie du sang ； et un tube de liaison (4) qui relie la section (2) de stockage de sang et la section (3) de réception de composant. La section (2) de stockage de sang comprend : un récipient (21) de stockage de sang en forme de tube, qui est souple ； un passage (27) d'entrée de sang qui achemine le sang dans le récipient (21) de stoc
