A blood purification apparatus with an arterial puncture needle or a venous puncture needle is stuck in the patient can be easily notified at the activation of a blood pump in an unconnected step. A blood purification apparatus includes a blood circuit for circulating blood, a dialyzer capable of purifying the blood, a blood pump provided to an arterial blood circuit for delivering a liquid, and a control device that executes a connected step in which the blood pump is activated when an arterial puncture needle (a) and a venous puncture needle (b) are in the patient and an unconnected step in which the blood pump is activated with neither the arterial puncture needle (a) nor the venous puncture needle (b) being stuck in the patient. The control device establishes, in the unconnected step, a restricted state where the behavior of the blood pump at the activation of the blood pump is restricted.