To provide a blood purification apparatus having a simple configuration while avoiding the increase in the manufacturing cost and in which the temperature of dialysate, if overheated, can be lowered in a shorter time and more easily. A blood purification apparatus includes a blood circuit (1), a dialyzer (2), a dialysate introduction line (L1), a dialysate drain line (L2), a blood pump (P1), a liquid delivery pump (P2), a filtration pump (P3), and a control device (9). The control device (9) is configured such that, if a dialysate temperature detected by the temperature-detecting device (T) is higher than or equal to a predetermined value, the liquid delivery pump (P2) is controlled to cause the dialysate in a heating device (h) to flow to an upstream side or a downstream side with respect to the heating device (h) without allowing the dialysate to be introduced into the dialyzer (2).
