Device for extracorporeal blood treatment (101) comprising: - a filter 102 having a primary chamber (103) and a secondary chamber (104) separated by a semipermeable membrane (105), - an extraction line (106) connected to the primary chamber (103) of the filter (102), - an extraction line (106) operatively associated with a first means for the regulation of the blood flow rate Qb (115), - a return line (108) to the output of the primary chamber (103) of the filter (102), - a first pre-infusion line (109) connected to a container of local anticoagulation substance (131) and connected to the extraction line (106) and operatively associated to a second means for regulating the flow rate of anticoagulation liquid Qpre1 (119), - a first post-infusion line (112) connected to a container of a restoration solution at least partially of the ionic balance of the blood (133) for the infusion of the solution in the blood and operatively associated with a third means for the regulation of the flow of the ionic equilibrium restoration solution Qpost1 (121), - an effluent line (110) connected to the outlet of the secondary chamber (104) of the filter (102) , connected to a drain tube and operatively associated with a fourth means for the regulation of the liquid flow of the liquid effluent Qeff (123), - a CPU (125) that includes a first means programmed to receive the signal emitted by at least one of the first, second, third and fourth means for regulating the flow of liquid (115, 119, 121, 123), characterized in that the CPU (125) also includes second programmed means for controlling at least the third means for regulating the flow of the ionic equilibrium restoration solution Qpost1 (121) as a function of the inlet flow rate equal to the blood flow rate Qb, water flow rate in the plasma Qpw or plasma flow rate Qp, effluent flow rate Qeff and flow rate l Qpre1 anticoagulation liquid, in which the second means of the CPU are programmed to control at least the third means to regula
