The present invention relates to a kind of equipment for extracorporeal blood treatment, the outlet 2 of fresh dialysis liquid with a device 1 supply is used for used dialyzate, balancing device 4 is for balancing fresh dialysis fluid and used dialyzate, ultrafiltration apparatus 15 and dialyzer 3, the latter is divided, and enters blood chamber 6 and dialysate chamber 7 by semi-permeable membrane 5. The invention additionally relates to a kind of for running the device for being used for extracorporeal blood treatment. The device of the invention is based on using the liquid level of 15 blood processor of ultrafiltration apparatus to rise the primary side dialysis liquid system I of separator 12 in the sky. In the apparatus of the present: invention, ultrafiltration apparatus 15 is designed to not only execute ultrafiltration mode, but also in ventilation mode. In ultrafiltration mode, ultrafiltration apparatus 15 is operated in such a way, i.e. used dialyzate exits the first air separator 12 of container 12A, although in ventilation mode, ultrafiltration apparatus 15 operates reversed, therefore the first air separator 12 of used dialyzate supply container 12A, since liquid level 12D rises in the first air separator of container.
