The invention relates to a method for flushing and/or for filling a blood treatment device in particular for priming a blood treatment device wherein the blood treatment device comprises at least one membrane filter in particular a hollow fiber membrane filter at least one first partial circuit and at least one second partial circuit wherein the first and the second partial circuits are separated by the membrane filter in a semipermeable manner wherein at least temporarily the first partial circuit is first filled with a fluid by means of a steady and/or pulsatile first volume flow wherein the volume flow does not exceed a specified threshold wherein at said threshold the membrane is not yet fully coated and/or permeated by the fluid and/or wherein the second partial circuit is open to the atmosphere at least temporarily and wherein air is forced from the first into the second partial circuit through the membrane of the membrane filter and/or wherein no vacuum is applied to the first partial circuit during filling.
