The medical elongated body (10) includes a shaft (20) having a lumen (26) through which a contrast agent can flow； and a tubular structure portion (24) which is provided at a distal portion of the shaft (20) and has an insertion hole (46) . The tubular structure portion (24) includes an inner tube (42) fixed to the distal portion of the shaft (20)； an outer tube (44) which is disposed radially outward of the inner tube (42) and is liquid-tightly fixed to the distal portion of the shaft (20) and a proximal portion of the inner tube (42)； a space portion (50) communicating with the lumen of the shaft (20) between the inner tube (42) and the outer tube (44), and an opening portion (56) through which a contrast agent flows from the lumen (26) into the space portion (50) flows out.
