Provided is a stent which is not easily displaced from a dwell site in a biological lumen and which has an excellent ability to follow a biological lumen. This stent (bile duct stent 100) is to dwell inside a biological lumen (bile duct B) and is provided with a stent main body section (110) having a cylindrical shape. The stent main body section is configured to be capable of expanding and contracting in the radial direction that is approximately orthogonal to an axial direction, has a relatively large expanding force in one portion (center portion) corresponding to the predetermined position at the indwelling site in the biological lumen, and a relatively small expanding force at other portions (both end portions) which have different positions in the axial direction from that of the one portion.