The invention relates to a mask (100) for the mechanical ventilation of a patient, comprising: a mask body made of flexible material, comprising a ventilation chamber (103), said mask body being provided with means (105) for connection to a respirator, and adhesive and gas-tight attachment means (10), comprising a peripheral edge (11) secured to the mask body and intended to surround at least the patient's nostrils, in order to hold in a tight manner the ventilation chamber at least around patient's nostrils.