The invention relates to a device for the automated determination of the PEEP of a patient. Said device comprises sensors and a suitable electronic system for determining a pressure-volume characteristic curve during a P/V maneuver. The electronic system is designed in such a way as to generate, specifically in terms of breathing pressure, the difference between "lung volume during exhalation (Vdef)" and "lung volume during inhalation (Vinf)", and to determine the maximum value of said difference. The breathing pressure is then determined, for which the volume difference has a value defined in relation to the maximum value of the volume difference. The device calculates a PEEP value on the basis of said determined breathing pressure value.
