Abstract: In a gravity-type separator for floating and sinking matter operating without a free level, both the separated floating matter and the separator content must be withdrawn or removed. According to the invention, this is accomplished with a pump that on the suction side has connecting ducts to the vertical center of the separator housing and the sinking matter outlet, and on the pressure side has connecting ducts to the waste water inlet duct and the clean water outlet duct. The pressurized water duct for the floating matter removal is taken from the inlet duct.