Balloon catheter

A balloon catheter extending in a longitudinal direction from a proximal side to a distal side comprising:

• a first shaft having a first lumen and a second lumen;
• a second shaft located distal to the first shaft;
• a balloon located distal to the second shaft;
• and
• an optical fiber disposed inside the balloon, wherein
• the first shaft is made of a resin,
• a cross-sectional area of the resin forming the first shaft is larger than each of cross-sectional areas of the first lumen and the second lumen in a cross section perpendicular to the longitudinal direction,
• the optical fiber is joined to a distal end of the first lumen to seal the distal end of the first lumen so that there is no gap at a joint portion between the distal end of the first lumen and the optical fiber, and the first lumen is not communicated with the second lumen through the joint portion,
• a proximal end of the balloon is joined to the second shaft, and
• a distal end of the balloon is joined to the optical fiber.