A peristaltic pump includes a mounting concave section 8a on which a peristaltically-actuated tube connected to an arterial blood circuit is mountable a roller which compresses the peristaltically-actuated tube mounted on the mounting concave section in a radial direction and causes the peristaltically-actuated tube to be peristaltically actuated in a longitudinal direction such that a liquid therein is flowable in the arterial blood circuit a load sensor that is able to detect displacement of the peristaltically-actuated tube 1a mounted on the mounting concave section in the radial direction and blockage detecting means that is able to detect a blockage of the arterial blood circuit based on the displacement detected by the load sensor.
