An anesthesia ventilator, for the automated ventilation of a patient, includes an expiratory port and an inspiratory port for connecting a patient ventilation tube for a breathing gas, a breathing gas delivery unit, a breathing gas volume flow sensor, a breathing gas sensor for detecting a carbon dioxide concentration, a pressure sensor for detecting a pressure of the breathing gas, and a computer. The computer is configured to actuate the breathing gas delivery unit in a first mode of operation as a function of a preset ventilation rate, of the detected pressure and of a preset desired pressure value. The computer is configured to detect the presence of a desired operating state concerning the automated ventilation on the basis of the detected volume flow and of the detected carbon dioxide concentration and to make possible a transition to a second mode of operation in case of detection.
