A blood purification apparatus in which the error in the amount of discharge from a blood pump that is caused by the change in the suction pressure of the blood pump is reduced. A blood purification apparatus includes a blood circuit through which blood of a patient is extracorporeally circulated; a dialyzer connected to proximal ends of an arterial blood circuit and a venous blood circuit and that purifies the blood extracorporeally circulating through the blood circuit; a squeezable tube connected to the arterial blood circuit; a blood pump allowing liquid in the squeezable tube to flow by squeezing the squeezable tube in a lengthwise direction while compressing the squeezable tube in a radial direction; and a pressure-detecting device attached to a predetermined position of the arterial blood circuit that is nearer to a distal end than a position where the blood pump is provided, the pressure-detecting device being capable of detecting a suction pressure of the blood pump.