A blood purification apparatus that includes a blood circuit including an arterial blood circuit and a venous blood circuit and being capable of extracorporeally circulating blood of a patient from a distal end of the arterial blood circuit to a distal end of the venous blood circuit; a blood purification device interposed between the arterial blood circuit and the venous blood circuit of the blood circuit and being capable of purifying the blood flowing in the blood circuit; a dialysate introduction line for introducing dialysate into the blood purification device, and a dialysate drain line for draining waste liquid from the blood purification device; a dialysate pump in a form of a peristaltic pump provided to the dialysate introduction line, the dialysate pump being capable of causing the dialysate in the dialysate introduction line to flow when the dialysate pump is activated to rotate; a dialysate storage bag connected to a distal end of the dialysate introduction line and that stores the dialysate to be introduced into the blood purification device; a waste-liquid pump in a form of a peristaltic pump provided to the dialysate drain line, the waste-liquid pump being capable of causing the waste liquid in the dialysate drain line to flow when the waste-liquid pump is activated to rotate; a waste-liquid storage bag connected to a distal end of the dialysate drain line and that stores the waste liquid drained from the blood purification device; a single weighing machine capable of measuring a total weight of the dialysate storage bag and the waste-liquid storage bag; and a control unit configured to control the dialysate pump and the waste-liquid pump in accordance with a value measured by the weighing machine, wherein the control unit is configured to calculate a correction value for a rotation speed of the dialysate pump or for a value associated with the rotation speed in accordance with a change in the value measured by the weighing machine in a process of activating the dialysate pump such that the dialysate in the dialysate storage bag is caused to flow without being stored in the waste-liquid storage bag, characterized in that the control unit is configured to execute a correcting process in which the rotation speed of the dialysate pump or the value associated with the rotation speed is corrected in accordance with the calculated correction value and in which the control unit activates the dialysate pump to rotate while keeping the waste-liquid pump stopped. a blood circuit including an arterial blood circuit and a venous blood circuit and being capable of extracorporeally circulating blood of a patient from a distal end of the arterial blood circuit to a distal end of the venous blood circuit; a blood purification device interposed between the arterial blood circuit and the venous blood circuit of the blood circuit and being capable of purifying the blood flowing in the blood circuit; a dialysate introduction line for introducing dialysate into the blood purification device, and a dialysate drain line for draining waste liquid from the blood purification device; a dialysate pump in a form of a peristaltic pump provided to the dialysate introduction line, the dialysate pump being capable of causing the dialysate in the dialysate introduction line to flow when the dialysate pump is activated to rotate; a dialysate storage bag connected to a distal end of the dialysate introduction line and that stores the dialysate to be introduced into the blood purification device; a waste-liquid pump in a form of a peristaltic pump provided to the dialysate drain line, the waste-liquid pump being capable of causing the waste liquid in the dialysate drain line to flow when the waste-liquid pump is activated to rotate; a waste-liquid storage bag connected to a distal end of the dialysate drain line and that stores the waste liquid drained from the blood purification device; a single weighing machine capable of measuring a total weight of the dialysate storage bag and the waste-liquid storage bag; and a control unit configured to control the dialysate pump and the waste-liquid pump in accordance with a value measured by the weighing machine, wherein the control unit is configured to calculate a correction value for a rotation speed of the dialysate pump or for a value associated with the rotation speed in accordance with a change in the value measured by the weighing machine in a process of activating the dialysate pump such that the dialysate in the dialysate storage bag is caused to flow without being stored in the waste-liquid storage bag, characterized in that the control unit is configured to execute a correcting process in which the rotation speed of the dialysate pump or the value associated with the rotation speed is corrected in accordance with the calculated correction value and in which the control unit activates the dialysate pump to rotate while keeping the waste-liquid pump stopped.