An extracorporeal blood treatment device is disclosed. The device includes a blood treatment unit connected to an extracorporeal blood circuit, a waste liquid discharge line for evacuating waste treatment liquid from the blood treatment unit, and a collecting container for collecting waste treatment liquid evacuated via the waste liquid discharge line. The collecting container is removably connected to the waste liquid discharge line via a one way valve. A collecting container for a device is also disclosed. The container includes a waste fluid input line, wherein a one way valve is arranged in the waste fluid input line.