Blood purification apparatus

A method to be executed by a blood purification apparatus provided with a blood circuit and a dialysate circuit coupled to each other through a blood purifier, a chamber provided to the blood circuit and configured to store the blood in the blood circuit, an air introduction route coupled to the dialysate circuit, an air introducer provided to any of the dialysate circuit and the air introduction route and configured to set the dialysate circuit to a positive pressure by introducing air into the dialysate circuit through the air introduction route, wherein the air introducer is coupled to the chamber and configured to adjust a liquid level in the chamber by feeding the air into the chamber, and a controller configured to control a pressure in the blood circuit and the dialysate circuit, wherein the blood circuit includes a blood removal side circuit which is a flow route for introducing blood into the blood purifier, and a blood return side circuit which discharges the blood from the blood purifier, the method comprising steps of:

• causing the controller to control the air introducer in such a way as to feed a dialysate from the dialysate circuit to the blood return side circuit;
• causing the controller to control the blood circuit and the dialysate circuit in such a way as to discharge blood in the blood removal side circuit and the blood purifier to a blood return side circuit by feeding the dialysate from the dialysate circuit to the blood return side circuit;
• and
• controlling, with the controller, the air introducer in such a way as to introduce the air into the dialysate circuit without feeding the air into the chamber in a case of discharging the blood in the blood removal side circuit and the blood purifier to the blood return side circuit.