A stent capable of retarding or preventing occlusion resulting from granulation includes: an outer annular body with a circular cross section in which an outer through-hole penetrating in a direction intersecting the radial direction of the circular cross section is formed and which can expand and contract in the radial direction； and an inner annular body disposed on the inside of the outer through-hole, forms a double annular cross section together with the outer annular body at least at the openings of the outer through-hole, and in which an inner through-hole penetrating in a direction that intersects with the radial direction of said circular cross-section is formed. When placed indwelling in a living body, the outer annular body can expand in the radial direction and can thereby support the living tissue with at least the opening of the inner through-hole of the inner annular body spaced from the living tissue.
