Facial protector for the prevention of pressure ulcers (upp) in patients undergoing non-invasive mechanical ventilation (nimv). The invention relates to a face shield that is placed under a non-invasive mechanical ventilation mask protecting the prominent areas of the nose and face preventing the friction of the mask and thus avoiding the high incidence of facial ulcers due to pressure and poor tolerance of the face. Mask of patients undergoing non-invasive mechanical ventilation. The protector is composed of a flexible antiallergic material that manages to seal the mask avoiding friction and pressure. (Machine-translation by Google Translate, not legally binding)