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 comprises: an airway main body wherein an elongated tongue plate curved in a longitudinal direction so as 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 hole for air and is adapted to fit into the airway main body, where the airway may be inserted into an oral cavity while the inward member is kept fitting in the main body, and only the inward member may be extracted after insertion.