An insertion apparatus includes a moving unit which moves between a first movement position in a state that the motion portion is in a movable state and a second movement position in a state that the motion portion is in the fixed state and a link unit including a first link, and a second link which is attached to the first link. The link unit includes a coupling portion which couples the first link with the second link in a state that the first link and the second link form a substantially V-like shape having the link coupling position as an apex when the moving unit is placed at the first movement position and in a state that the first link and the second link form a substantially linear shape that does not bend at the link coupling position when the moving unit is placed at the second movement position.