A balloon catheter including: a flexible sheath which has at least one lumen and a cylindrical balloon which is fixed to the outer peripheral surface of the sheath and can be inflated with a fluid supplied from the lumen wherein the sheath has a large diameter portion whose outer diameter is greater than a basic outer diameter thereof, and the balloon is set to have a maximum inner diameter greater than the basic outer diameter when deflated, and is attached to the outer peripheral surface of the large diameter portion.
