Balloon catheter

A balloon catheter comprising:

• a first sub-tube, which extends in the lengthwise direction, has a first end and a second end, and has a first passage formed therein in order for a fluid to be injected therethrough;
• a second sub-tube, which is attached to an outer circumference of the first sub-tube and has a first end located at a same position as the first end of the first sub-tube, an extension section extending beyond the second end of the first sub-tube and having a second passage formed therein and a through-hole formed in an outer circumference thereof, and a second end having an opening communicating with the extension section, the second passage communicating with the first end of the first sub-tube in order for the fluid to be introduced from the first passage;
• and
• a balloon disposed on the extension section of the second sub-tube in order for the fluid to be introduced from the through-hole.