A blood separating device according to the present invention may advantageously separate a platelet rich plasma without making blood in a container moved to another container after the blood is firstly and secondly centrifuged. Moreover, a first valve means may be opened by the rotation of any one of a first case and a second case, so a blood corpuscle component and a plasma component may be easily separated. Furthermore, a second valve means may be opened by the rotation of any one of the second case and a third case, so a platelet rich plasma and a platelet poor plasma may be easily separated. Since the degree of opening is adjusted according to rotation angles of the first and second valve means, a boundary surface between a plasma component and a blood corpuscle component or a boundary surface between a platelet rich plasma and a platelet poor plasma may be more easily and precisely separated. The first and second valve means are formed to be opened when each of opening parts is opened, so an opened flow path area is minimized and a small quantity of a plasma component or a platelet rich plasma may be more precisely fed and discharged. Accordingly, blood separation may be more easily performed. The first and second valve means are formed to be gradually opened and to be gradually shielded according to rotation angles thereof, so a small quantity of a plasma component or a platelet rich plasma may be more slowly fed and discharged and of a boundary surface therebetween may be more precisely separated. A platelet rich plasma separated and accommodated in the third case is extracted by using a syringe and may be immediately fed into a patient. Consequently, blood is not exposed to air, and occurrence of contamination may be prevented.본 발명에 따른 혈액 분리 장치는, 1,2차 원심 분리 후 혈액을 다른 용기로의 이동 없이 다혈소판혈장을 분리할 수 있는 이점이 있다. 또한, 제1케이스와 제2케이스 중 어느 하나의 회전으로 제1밸브수단의 개방이 가능하여, 혈구 성분과 혈장 성분의 분리가 용이하다. 또한, 제2케이스와 제3케이스 중 어느 하나의 회전으로 제2밸브수단의 개방이 가능하여, 다혈소판 혈장과 빈혈소판 혈장의 분리가 용이하다. 또한, 제1,2밸
