After driving the upstream side closing member 31 and the downstream side closing member 35 in the pressing direction to close the liquid transfusing tube 102, the driving unit 40 moves the prescribed force pressing member 32 in the pressing direction to raise the internal pressure of the infusion tube 102 . Thereafter, the specified amount pressing member 34 is moved in the pressing direction, and the downstream side closing member 35 is moved in the anti-pressing direction to open the downstream side of the liquid transfusing tube 102.駆動部40は、上流側閉塞部材31及び下流側閉塞部材35を押圧方向に移動させて輸液チューブ102を閉塞した後、規定力押圧部材32を押圧方向に移動させて輸液チューブ102の内圧を高める。その後、規定量押圧部材34を押圧方向に移動させるとともに、下流側閉塞部材35を反押圧方向に移動させて輸液チューブ102の下流側を開放する。
