The invention relates to a device for separating a gas-liquid mixture, in which the liquid portion exists in the form of small particles, especially for ventilating a crankcase of an internal combustion engine, by separating and coagulating the liquid particles on a target area. The liquid mixture, after acceleration in acceleration openings provided for this purpose, impacts the target area at an approximately right angle. The aim of the invention is to improve the aforementioned device in such a manner that it allows as high a degree of separation as possible for different sized volume flows of mixtures. For this purpose, the number and/or the cross-sections of the acceleration openings (5, 6) is varied, depending on the volume flow of mixtures, between a small complete cross-section for a low volume flow and a large complete cross-section for a large volume flow.