[Object] Disclosed is a blood purification apparatus that is able to prevent a user from forgetting to connect a dialysate infusing line by automatically confirming the connection of the dialysate infusing line to a collection port that is formed in a predetermined part on a dialysis fluid introduction line. [Solution] The blood purification apparatus is equipped with a dialyzer 1, an arterial blood circuit 2 in which a blood pump 4 has been disposed, a venous blood circuit 3, the dialysis fluid introduction line L1, a dialysis fluid discharge line L2, the dialysate infusing line L8, and a dialysate infusing pump 13, wherein a closed circuit is formed in the flow route of the dialysis fluid on the dialysis fluid introduction line L1 side including the predetermined part where the collection port 11 has been formed, and a testing process for confirming the connection of the dialysate infusing line L8 to the collection port 11 is performed by measuring the fluid pressure within the closed circuit while driving the dialysate infusing pump 13.
