[Object] Providing an extracorporeal circulation device with which the risk of generation of an air bubble is alleviated and the state of a patient is also easily determined. [Solution] An extracorporeal circulation device is characterized by including a blood removal line 11 through which blood withdrawn from the inside of the body of a subject passes, a centrifugal pump 4 that is connected downstream of the blood removal line 11 and carries out blood sending by rotational motion, an oxygenator 2 connected downstream relative to the centrifugal pump 4, a blood sending line 12 that is downstream relative to the oxygenator 2 and returns blood to the inside of the body, and a flow rate sensor 52 that detects a blood flow rate in the blood sending line 12. The extracorporeal circulation device includes an intermediate part pressure sensor 37 that is a pressure sensor that detects pressure in a circuit between the centrifugal pump 4 and the oxygenator 2, and a controller 10 that identifies discharge pressure specific to the centrifugal pump 4 based on the rotation speed of the centrifugal pump 4 and the blood flow rate detected in the flow rate sensor 52.
