A dialysis apparatus has a dialysate infusing line. One end of the dialysate infusing line is connected to the dialysate introducing line or the dialysate discharging line. The other end is branched out at a branch point into two flow routes, respectively, a first branch end and a second branch end. The first branch end is connectable to the arterial blood circuit or the venous blood circuit. The second branch end is connectable to the tip end of the arterial blood circuit during the blood-returning process. A dialysate infusing pump is arranged on the dialysate infusing line at a connection-side of the dialysate infusing line relative to the dialysate introducing line or the dialysate discharging line from the branch point. The dialysate infusing pump supplies the dialysate of the dialysate introducing line or the dialysate discharging line to the first branch end and the second branch end.