A catheter is disclosed, which includes an inner tube, and a coil tube disposed on an outer peripheral side of the inner tube, the inner tube being a coil obtained by winding a wire. In addition, in the coil tube, a first coil and a second coil are arranged concentrically with each other. The first coil and the second coil have mutually different winding directions of the wire. Then, the inner tube and the coil tube are rotatable relative to each other around a central axis of the coil tube. In addition, in a natural state where no external force is applied to the catheter, a gap is formed between the inner tube and the coil tube.
