A flexible tube portion (25) includes a spiral tube (81), a first connecting tube (111) which is arranged on a distal end portion (81a) side of the spiral tube (81) and a second connecting tube (121) which is arranged on a proximal end portion (81b) side of the spiral tube (81). The spiral tube (81) is movable along an axial direction of the spiral tube (81) with respect to at least one of the first connecting tube (111) and the second connecting tube (121).
