A placement device (10) for a blood vessel treatment instrument has an introducer sheath (14) functioning as an outer tube, and also has an inner tube (16). The introducer sheath (14) has a flexible tube-shaped sheath body (18) and a hub (20) into which the base end of the sheath body (18) is inserted. The hub (20) takes up the base end of the sheath body (18) into the hub (20) by means of take-up shafts (30, 32) while tearing the base end of the sheath body (18) by cutting blades (72, 74), and thus the length of extension of the sheath body (18) from the hub (20) can be shortened.
