An object of the present invention is to provide a stent (1, 3) excellent in stabilizing the bloodstream, for example, a stent (1, 3) capable of sufficiently suppressing the bloodstream flowing into an aneurysm when indwelt at an inlet of the aneurysm. The stent (1, 3) of the present invention includes a first strand group (2A) and a second strand group (2B) which are woven together. The first strand group (2A) is wound in a right-handed spiral around a virtual central axis (L) that extends in the longitudinal direction of the stent (1, 3). The second strand group (2B), on the other hand, is wound in a left-handed spiral around the virtual central axis (L). Furthermore, the diameter (Da) of each of a plurality of first strands (2a) constituting the first strand group (2A) is different (either larger or smaller) than the diameter (Db) of each of a plurality of second strands (2b) constituting the second strand group (2B).