The blood component picking device (10), the intermediate bag (126a) centrifugal separating before the blood platelet transport process which transports the thick blood platelet inside, at the time of 1st cycle, the blood plasma which can just place fixed quantity the intermediate bag (126a) does the blood plasma introduction process which is introduced. Because the blood plasma whose anti- solidification medicine density is high is introduced the intermediate bag (126a) beforehand, the intermediate bag (126a) it can control the occurrence of the cohesion lump of the thick blood platelet in inside.血液成分採取装置(10)は、第1サイクル時に中間バッグ(126a)内に濃厚血小板を移送する血小板移送工程の前に、遠心分離して得られた血漿を所定量だけ中間バッグ(126a)に導入する血漿導入工程を行う。抗凝固剤濃度が高い血漿が予め中間バッグ(126a)に導入されるため、中間バッグ(126a)内での濃厚血小板の凝集塊の発生を抑制することができる。
