In the space between an outer tube (14) and an inner tube (12) that configure a stent delivery system (10), a cylindrical mesh reinforcing spacer (52) is provided at a position that is on the base end side of a stent (16). The reinforcing spacer (52) is provided to be freely movable in the axial direction and radial direction. Even when the outer tube (14) and the inner tube (12), which have been advanced into the lumen of a living body, are bent, the reinforcing spacer (52) moves in the axial and radial directions and elastically deforms, thereby maintaining a substantially uniform internal circumference for the outer tube (14) along the axial direction.
