The purpose of the present invention is to provide a continuous blood purification apparatus that can stop the substitution fluid pump, at least at the stage when the blood return chamber is filled with the substitution fluid, when the channel from the substitution fluid tank to the substitution fluid clamp is closed during operation of the substitution fluid pump. This continuous blood purification apparatus is provided with an extracorporeal blood circulation circuit (10), a dialysate channel (20), a substitution fluid channel (30), a waste fluid channel (40), a volume measurement means, and a control unit. The substitution fluid tank (31), the substitution fluid clamp (32) and the substitution fluid pump (33) are disposed in the substitution fluid channel (30). A substitution fluid branch channel (35), wherein are disposed a substitution fluid measuring solenoid valve (36), an upper substitution fluid level sensor (37), a substitution fluid measurement vessel (38) and a lower substitution fluid level sensor (39), is connected to the substitution fluid channel (30) between the substitution fluid clamp (32) and the substitution fluid pump (33). The control unit outputs a warning signal and a pump stop signal when a situation in which the substitution fluid level is positioned below the lower substitution fluid level sensor (39) continues for a certain time during the operation of the substitution fluid pump (33).La présente invention a pour but de proposer un appareil de purification continue de sang qui peut arrêter la pompe à fluide de substitution, au moins à létape à laquelle la chambre de renvoi de sang est remplie avec le fluide de substitution, lorsque le canal allant du réservoir de fluide de substitution à la bride de fluide de substitution est fermé pendant le fonctionnement de la pompe à fluide de substitution. Lappareil de purification continue de sang de la présente invention comporte un circuit de circulation extracorporelle de sang (10), un canal de
