A blood purification apparatus employing a single-needle double-pump method and being capable of automatically discharging a priming solution that has undergone substitution from a blood circuit during blood removal. A blood purification apparatus includes a blood circuit to which an only puncture needle is connectable, a dialyzer that purifies blood flowing in the blood circuit, a first blood pump, a second blood pump, and a control device that allows the blood of a patient to be extracorporeally circulated through the blood circuit by causing the first blood pump and the second blood pump to alternately undergo normal rotation. During blood removal, the control device operates to substitute a priming solution in the blood circuit with the blood of the patient and to discharge the priming solution having undergone the substitution from the blood circuit by causing the first blood pump to undergo normal rotation and the second blood pump to undergo reverse rotation.
