An object of the present invention is to provide a balloon catheter capable of preventing balloon rupture and treatment in a balloon shape unsuitable for treatment by forcibly allowing liquid to pass when the balloon is stretched. The present invention has an inner cylindrical shaft having a small-diameter inner cylindrical portion on the distal end side and a large-diameter inner cylindrical portion on the proximal end side, an outer cylindrical shaft in which the inner cylindrical shaft is inserted into a lumen, The distal end is fixed to the distal end of the inner cylindrical shaft, the proximal end is fixed to the distal end of the outer cylindrical shaft, and the outer cylindrical shaft and the inner cylindrical shaft slide relative to each other. A balloon having a shape that changes between expanded shapes, and a housing that communicates with the lumen of the outer cylinder shaft and has a small-diameter lumen on the distal end side and a large-diameter lumen on the proximal end side, and balloon expansion Provided is a catheter with a balloon in which insertion of a liquid into the balloon is blocked by inserting a large-diameter inner cylinder portion of the inner cylinder shaft into a small-diameter lumen of the housing when shaped.本発明はバルーン伸張形状時に無理に通液させることによるバルーンの破裂及び治療に適さないバルーン形状での治療を防ぐことが可能なバルーン付きカテーテルを提供することを目的とする。本発明は先端側に小径の内筒部を有し、かつ、基端側に大径の内筒部を有する内筒シャフトと、上記内筒シャフトが内腔に挿入された外筒シャフトと、先端が上記内筒シャフトの先端に固定され、かつ、基端が上記外筒シャフトの先端に固定され、上記外筒シャフトと上記内筒シャフトが相互に摺動することにより、バルーン平常形状とバルーン伸張形状の間で形状が変化するバルーンと、上記外筒シャフトの内腔と連通し、先端側に小径の内腔及び基端側に大径の内腔を有するハウジングと、を備え、バルーン伸張形状時に上記内筒シャフトの大径の内筒部が前記ハウジングの小径の内腔に挿入されることで、前記バルーンへの液体の挿入が遮断される、バルーン付きカテーテルを提供する。
