The invention refers to an extracorporeal blood treatment device, said device comprising a blood treatment unit connected to an extracorporeal blood circuit, a waste liquid discharge line (1, 2, 3, 26) for evacuating waste treatment liquid from the blood treatment unit and a collecting container (11, 13, 31) for collecting waste treatment liquid evacuated via the waste liquid discharge line (1, 2, 3, 26), wherein the collecting container (11, 13, 31) is removable connected to the waste liquid discharge line (1, 2, 3, 26) via a one way valve (22, 23, 24, 25, 32, 33). The invention further refers to a collecting container (11, 13, 31) for a device according to one of the preceding claims, which container (11, 13, 31) comprises a waste fluid input line (10, 12, 30), wherein a one way valve (24, 25, 32) is arranged in the waste fluid input line (10, 12, 30).
