In a blood purification apparatus in which an infusion line for supplying an infusion solution such as an anticoagulant is connected to the blood removal line, the blood pump does not rotate in the reverse direction, and no infusion supply means for returning blood is provided downstream of the blood pump. , Automatically return blood. The control unit 80 of the blood purification apparatus 1 stops the operation of the blood pump 30 and the infusion pump 52, opens the first infusion line 40 with the first on-off valve 42, closes the blood removal line 10 with the second on-off valve 11, The blood pump 30 is rotated forward by a predetermined amount X to move the first infusion from the first infusion line 40 to the blood removal line 10, and the infusion pump 52 is reversed by a predetermined amount Y to move the first infusion line 10 Move the infusion to the second infusion line 50, close the first infusion line 40 with the first on-off valve 42, open the blood removal line 10 with the second on-off valve 11, and rotate the infusion pump 52 by a predetermined amount Z forward. The first infusion in the second infusion line 50 is moved to the blood removal line 10 and returned to the patient P. This realizes automatic blood return to the patient P.抗凝固剤等の輸液を供給する輸液ラインを脱血ラインに接続した血液浄化装置において、血液ポンプの逆回転を行うことなく、かつ、血液ポンプ下流側に返血用輸液供給手段を設けることなく、自動で返血を行う。血液浄化装置1の制御部80は、血液ポンプ30及び輸液ポンプ52の運転を停止させ第一開閉弁42で第一輸液ライン40を開放し第二開閉弁11で脱血ライン10を閉塞し、血液ポンプ30を所定量X正転させて第一の輸液を第一輸液ライン40から脱血ライン10へと移動させ、輸液ポンプ52を所定量Y逆転させて脱血ライン10内の第一の輸液を第二輸液ライン50へと移動させ、第一開閉弁42で第一輸液ライン40を閉塞し第二開閉弁11で脱血ライン10を開放し、輸液ポンプ52を所定量Z正転させ第二輸液ライン50内の第一の輸液を脱血ライン10へと移動させて患者Pへと戻す。これにより患者Pへの自動返血を実現させる。
