An oral airway, which is used by being inserted into the mouth of a patient who is suffering from unconsciousness or has lost consciousness to secure an airway of the patient, is adapted to be used with a tube to be inserted into the trachea of the patient through the mouth thereof. The oral air way includes a main body, and an insertion part provided on the main body. The insertion part is adapted to be inserted into the trachea of the patient through the mouth thereof so that an appropriate portion of the insertion part at the side of the distal end thereof comes into contact with the root of the tongue of the patient to secure the airway of the patient. The insertion part includes a guide groove for guiding the tube when the tube is inserted into the trachea of the patient, and the guide groove has a structure from which the tube can be separated after the distal end of the tube has been inserted into the trachea of the patient.