PROBLEM TO BE SOLVED: To provide an indwelling needle capable of preventing the mixing-up of an indwelling needle for blood removal and an indwelling needle for blood supply, and an extracorporeal circulation apparatus.SOLUTION: An extracorporeal circulation apparatus 1 used together with an indwelling needle 20 having a marker part capable of detecting a puncture direction by an ultrasonic wave includes an extracorporeal circulation management device 10 for managing the extracorporeal circulation apparatus 1. An ultrasonic measurement device 40 for measuring a blood flow of an object person P is connected to the extracorporeal circulation management device. The ultrasonic measurement device emits a plurality of ultrasonic waves to the blood flow of the object person, receives reflected sound waves, and, from the difference information of the reflected sound waves, generates direction information on the blood flow and puncture direction information on the indwelling needle. The direction information on the blood flow and the puncture direction information are displayed in a display part 51 of the extracorporeal circulation management device.SELECTED DRAWING: Figure 2【課題】脱血用留置針及び送血用留置針の取り違えを未然に防止可能な留置針及び体外循環装置を提供すること。【解決手段】超音波によって穿刺方向が検知可能な標識部を有する留置針２０と共に使用し、体外循環装置１を管理する体外循環管理装置１０を備え、体外循環管理装置には、対象者Ｐの血流を測定する超音波測定装置４０が接続され、超音波測定装置は、対象者の血流に複数の超音波を発射して、受信し、これらの反射音波の差異情報から、血流の方向情報と留置針の穿刺方向情報を生成し、血流の方向情報と穿刺方向情報を，体外循環管理装置の表示部５１に表示する体外循環装置１。【選択図】図２
