Abstract: A stent for a vessel inserted in use into the vessel of a living body including a tubular member constituting a passageway from one end to its opposite end. The tubular member includes a main mid portion and low tenacity portions formed integrally with both ends of the main mid portion. The low tenacity portions are lower in tenacity than the main mid portion. These low tenacity portions are formed so as to have the Young's modulus approximate to that of the vessel of the living body in which is inserted the stent, so that, when the stent is inserted into the vessel, it is possible to prevent stress concentrated portions from being produced in the vessel.