A stent delivery system includes a distal-side tube, a proximal-side tube, a fixing tube, a stent containing tubular member, a stent in the stent containing tubular member, and a pulling wire for moving the stent containing tubular member to the proximal side. The distal-side tube includes a distal-side priming slit provided in a side wall in proximity to a stent proximal end lock section and a proximal-side priming slit provided in a side wall on the proximal side of the distal-side tube. The slits are opened by injecting liquid, with the distal opening or the rear end opening of a guide wire lumen of the distal-side tube closed.