Endotracheal intubation support instrument comprises: a main body section having flexibility; a handle section and a blade section extending from both sides of the main body section respectively; and a U-shaped groove running through the main body section from the handle section to the blade section and allowing a flexible tube of a bronchial fiber to come in and out freely. The blade section comprises: a flap for subsuming all or a part of a larynx of a patient; and a lifting body having, on each bank of the U-shape groove, a first protruding portion allowed to contact with a peripheral portion of an epiglottis of the patient and a second protruding portion provided next to a main body section side of the first protruding portion and allowed to contact with a peripheral portion of a glossal root of the patient.