An extracorporeal circulator is disclosed comprising a line for extracting blood from a patient, a pump for supplying blood, an artificial lung section performing gas exchange on blood, a line for supplying blood passed through the artificial lung section to the patient, a unit for removing bubbles mixed into the blood, a means for controlling the flow rate of blood being supplied such that bubbles are not fed to the patient, and a line for detouring blood delivered from the blood pump to return it to the blood pump.
