In an adjuster for an airway securing device, a base member fixed to one of an upper jaw side attachment body and a lower jaw side attachment body is provided with a base member side half tube part and a slide member fixed to the other of the upper jaw side attachment body and the lower jaw side attachment body is provided with a slide member side half tube part. The base member side half tube part and the slide member side half tube part form a tube part in which an adjusting bolt is disposed on its inner peripheral side. A base member side flange part is formed at a base end of the base member side half tube part and a slide member side flange part shape is formed at a base end of the slide member side half tube part.
