The invention relates to a method for deaerating a dialyser comprising a dialysate chamber, a blood chamber, and a semi-permeable dialyser membrane which separates these two chambers, wherein, in order to remove entrapped air present on the dialysate chamber-side surface of the membrane, an excess pressure in relation to the blood chamber is produced in the dialysate chamber once said dialysate chamber has been filled and before the blood chamber is filled.