A medical instrument which improves a state of falling of a tongue root of a patient to makes it easy to maintain an air passage in a pharynx portion. An airway of the present invention includes an airway main body wherein an elongated tongue plate curved in a longitudinal direction to match a curved surface shape of a tongue, and an elongated palate plate curved approximately similarly to the elongated tongue plate, are connected by two side plates and an inward member which includes a groove portion provided on the surface of the inward member to define a hole for air to pass air therethrough when the inward member fits into the airway main body.