Blood purification device

A blood purification device that does not require measurement of a patient's blood concentration performed ahead of time and that allows treatment time to be reduced, thus reducing the burden on the patient, and allows monitoring of problems in the internal elements. The present invention includes: blood purification device main units including a blood pump disposed in an arterial blood circuit, a blood purification device purifying blood, and an ultrafiltration pump for draining water from blood; first measuring means and second measuring means measuring hematocrit values and disposed at the arterial blood circuit and the venous blood circuit respectively; calculating means calculating a ratio for measured hematocrit values and a ratio for a theoretical hematocrit values determined from a predetermined equation and evaluating means evaluating whether the values determined by calculating means are roughly similar.