A laryngeal mask for securing an airway of a patient, comprising: an insertion tube including a base end in which is formed a connecting portion capable of being connected to an artificial respirator, a leading end in which is formed a ventilation opening, and a communication passage formed therein that communicates between the connecting portion and the ventilation opening; a ring-shaped cuff which is attached to the leading end of the insertion tube so as to surround the ventilation opening, and is capable of tightly adhering to a tracheal opening of a patient trachea as a result of inflating in a state where the ring-shaped cuff is inserted to a predetermined insertion position in the patient; at least one hyoid bone-contacting portion (6d; 6e) that protrudes laterally from the insertion tube so as to contact from above a site, in a pharyngeal portion of the patient, corresponding to a hyoid bone of the patient in a state where the ring-shaped cuff is inserted to the insertion position: and a positioning member fixed to the insertion tube, wherein the at least one hyoid bone-contacting portion (6d; 6e) is formed on the positioning member, the positioning member has an extending portion in the shape of a flat plate that extends farther towards the leading end side than the leading end of the insertion tube, the insertion tube is provided with an outer tube and an inner tube inserted inside the outer tube, the ring-shaped cuff is provided with a bottom portion in the shape of a flat plate corresponding to the positioning member, a ring-shaped cuff body provided over the entire periphery of the peripheral edge of the bottom portion, an outer tube attaching portion configured to attach the outer tube, inner tube attaching portions (7d, 7f) configured to attach the inner tube, and a gas supply and evacuation portion configured to supply and evacuate a gas to and from the ring-shaped cuff body, a surface on one side of the ring-shaped cuff body is configured to tightly adhere to the tracheal opening of the trachea over the entire periphery thereof, the extending portion of the positioning member is introduced to the inside of the ring-shaped cuff body through a through hole formed in the bottom portion. an insertion tube including a base end in which is formed a connecting portion capable of being connected to an artificial respirator, a leading end in which is formed a ventilation opening, and a communication passage formed therein that communicates between the connecting portion and the ventilation opening; a ring-shaped cuff which is attached to the leading end of the insertion tube so as to surround the ventilation opening, and is capable of tightly adhering to a tracheal opening of a patient trachea as a result of inflating in a state where the ring-shaped cuff is inserted to a predetermined insertion position in the patient; at least one hyoid bone-contacting portion (6d; 6e) that protrudes laterally from the insertion tube so as to contact from above a site, in a pharyngeal portion of the patient, corresponding to a hyoid bone of the patient in a state where the ring-shaped cuff is inserted to the insertion position: and a positioning member fixed to the insertion tube, wherein the at least one hyoid bone-contacting portion (6d; 6e) is formed on the positioning member, the positioning member has an extending portion in the shape of a flat plate that extends farther towards the leading end side than the leading end of the insertion tube, the insertion tube is provided with an outer tube and an inner tube inserted inside the outer tube, the ring-shaped cuff is provided with a bottom portion in the shape of a flat plate corresponding to the positioning member, a ring-shaped cuff body provided over the entire periphery of the peripheral edge of the bottom portion, an outer tube attaching portion configured to attach the outer tube, inner tube attaching portions (7d, 7f) configured to attach the inner tube, and a gas supply and evacuation portion configured to supply and evacuate a gas to and from the ring-shaped cuff body, a surface on one side of the ring-shaped cuff body is configured to tightly adhere to the tracheal opening of the trachea over the entire periphery thereof, the extending portion of the positioning member is introduced to the inside of the ring-shaped cuff body through a through hole formed in the bottom portion.