PROBLEM TO BE SOLVED: To provide a mirror catheter for inexpensively and easily observing the back side of a raised wall such as a fold in endoscopy of a body lumen such as the large intestine. A mirror catheter (1) is provided with a catheter tube (11) in which a fluid lumen through which a fluid can flow is formed in an axial direction, and a catheter (11) provided on the distal end side of the catheter tube (11) for the fluid supplied through the fluid lumen. A balloon portion 30 that can be expanded and contracted by pressure, and the balloon portion 30 includes a mirror layer that reflects light from the outside of the balloon portion 30. [Selection diagram] Figure 1【課題】大腸等の体内管腔の内視鏡検査において襞等の隆起壁の裏側を安価かつ簡便に観察するためのミラーカテーテルを提供する。【解決手段】ミラーカテーテル１は、流体が流通可能な流体ルーメンが軸方向に形成されたカテーテルチューブ１１と、カテーテルチューブ１１の遠位端側に設けられ、流体ルーメンを介して供給される流体の圧力により膨縮可能なバルーン部３０と、を備え、バルーン部３０は、バルーン部３０の外部からの光を反射するミラー層を含む。【選択図】図１
