This catheter is provided with: a tube body having a first hole that extends in an axial direction； an optical fiber disposed in the first hole； a ring-shaped marker that is disposed around the outer periphery of a leading end of the tube body； a first fixing member that is fixed to the optical fiber in such a manner as to be situated at one side of the marker in the axial direction and that has an outer width greater than an inner width of the first hole in at least one direction perpendicular to the axial direction； and a second fixing member that is fixed to the optical fiber in such a manner as to be situated on the other side of the marker in the axial direction and that has an outer width greater than the inner width of the first hole in at least one direction perpendicular to the axial direction.
