Disclosed is a ventilator comprising a ventilation device which produces a respiratory gas flow for ventilating at least one patient and sets the respiratory gas flow to at least one ventilation pressure depending on at least one respiratory phase of the patient. Provision is made of a monitoring device which is suitable and configured for monitoring a synchronicity between respiratory phase and target ventilation pressure and, to this end, capturing a characteristic signal for the ventilation pressure and a characteristic signal for the respiratory phase of the patient and comparing the two signals to one another and determining a characteristic for the synchronicity on the basis of the comparison.
