A catheter includes a flexible tube-shaped main catheter body, a hub connected to a proximal portion of the main catheter body, and a strain relief supported by a distal portion of the hub, the strain relief surrounding a predetermined range of a proximal side of the main catheter body. The strain relief includes a hard portion which is provided in each of regions opposite from each other with respect to an axis in at least a distal-side portion, and which is configured to be harder than another portion in a circumferential direction.
