An intubation assistance instrument which is used by being inserted into the trachea of a patient through the mouth thereof includes an insertion section having a straight portion with a tip part and a curved portion continuously extended from the tip part of the straight portion. The insertion section is formed with a groove along a longitudinal direction thereof. The curved section has an inner wall part and an outer wall part which define the groove, and the outer wall part is formed with a cut out portion other than a tip part of the curved portion. The intubation assistance instrument and an intubation assistance apparatus provided with the instrument make it possible to carry out intubation operation with simple operation easily and safely.