An insertion path securing apparatus includes a bending-insertion assisting instrument and a sheath tube that includes a first lumen where the bending-insertion assisting instrument is inserted. The bending-insertion assisting instrument includes a bendable tip bending portion, an intermediate extension portion being connected to the tip bending portion, and a bending operation portion being disposed at a base end of the intermediate extension portion. The state of the intermediate extension portion can be selectively switched to a variable-shape state where the bent shape of the intermediate extension portion can be freely changed and a shape retaining state where the bent shape of the intermediate extension portion is retained. The sheath tube includes a tube-like insertion portion of which the state can be selectively switched to a variable-shape state and a shape retaining state, and an operation portion that is disposed at a base end of the tube-like insertion portion.