Provided is a treatment device capable of improving convenience during treatment. The treatment device 4 includes: a catheter 1 that has a delivery shaft 11 which extends along an axial direction (Z axis direction)； a stent graft 2 that has a graft 22 and a stent 21, which are cylindrical, and that has a stent disposed region A41 and a stent non-disposed region A42 along the axial direction； and a cover 3 for maintaining the stent graft 2 in a diameter-reduced state at a distal region A1 of the delivery shaft 11. The cover 3 includes: a cylindrical outer layer portion 32； an inner layer portion 31 which is positioned inboard of the outer layer portion 32 and maintains the stent graft 2 in the diameter-reduced state inboard thereof； a folded portion 33 which connects the outer layer portion 32 to the inner layer portion 31 at the distal end side of the delivery shaft 11； and markers 31M which are disposed on the inner layer portion 31 in a region facing the stent non-disposed region A42 and which are visible from outside through the outer layer portion 32.本發明提供一種可以提升治療時的便利性的治療裝置。治療裝置4具備：導管1，其具有沿著軸向(Z軸方向)延伸的傳送軸11；覆膜支架2，其以包括管狀移植物22及支架21的方式構成，並且沿著軸向具有支架配置區域A41及支架未配置區域A42；以及蓋件3，其用於在傳送軸11的前端區域A1使覆膜支架2保持在收縮狀態。蓋件3具有：筒狀的外層部32；內層部31，位於外層部32的內周側，並且在自身的內周側覆膜支架2以收縮狀態保持；折返部33，其在傳送軸11的前端側，連接外層部32與內層部31；以及標記31M，其以配置於內層部31的與支架未配置區域A42對向的區域，並且可以透過外層部32從外部視認的方式構成。
