In addition to the challenge] pressure resistance, and to provide a balloon and balloon catheter that can work to improve operability. A tubular body 12 having a transportable flexible drive fluid and communicates by connecting the distal end of the tubular body A1 A balloon catheter 10, the inflation and deflation balloon innermost layer 112 by a flow discharge of drive fluid and, and a tapered portion 115 of the second reduced diameter toward the axial direction base end side of the tubular body and the tapered portion 113 of the first reduced in diameter toward the axial tip side of the tubular body, inflation of the balloon innermost layer and a, a balloon outer layer 110 of the at least one cover the inflating and deflating balloon innermost layer by contraction, one of the tapered portion and the second tapered portion of the first, a first at least one of the balloon outer I have a fragile portion 117 to reduce the rigidity of the tapered portion. [Selection Figure Figure 2【課題】耐圧性に加え、操作性向上を図り得るバルーンカテーテル及びバルーンを提供する。【解決手段】バルーンカテーテル10は、駆動流体を移送可能な可撓性を有する管状体12と、管状体の先端に接続して連通し、駆動流体の流入排出によって膨張収縮可能なバルーン最内層112と、管状体の軸方向先端側に向かって縮径する第1のテーパ部113及び管状体の軸方向基端側に向かって縮径する第2のテーパ部115を備え、バルーン最内層の膨張収縮によって膨張収縮可能なバルーン最内層を覆う少なくとも1つのバルーン外層110と、を有し、バルーン外層のうちの少なくとも1つは、第1のテーパ部及び第2のテーパ部のうち、少なくとも第1のテーパ部に剛性を低下させる脆弱部117を有する。【選択図】図2
