An insertion device includes: a linear member 40u, 40d inserted into an insertion portion to be movable a plurality of mobile bodies 78u, 78d provided in a state of being strung together on an outer periphery of the linear member 40u, 40d and being movable with respect to the linear member 40u, 40d a restricting member 62u, 62d, 78uh, 78dh fixed with respect to the linear member 40u, 40d, the restricting member restricting a movable range of each mobile body 78u, 78d with respect to the linear member 40u, 40d and preventing each of the mobile bodies78u, 78d from falling off and a fixing pin 77x, 77y being movable between a first position and a second position at which the fixing pin is fitted in between any adjacent two mobile bodies.
