A balloon catheter is disclosed. The balloon catheter includes an outer tube, a solid rigid rod, a balloon, markers and a body unit. The rigid rod is inserted into the outer tube such that a gap is defined between the rigid rod and the inner surface of the outer tube. The front and rear ends of the rigid rod extend outwards from the outer tube. The front end of the balloon is fastened to the front end of the rigid rod. The rear end of the balloon is fastened to the front end of the outer tube. The markers are fastened to the rigid rod in the balloon at opposite positions spaced apart from each other. The body unit is fastened to the rear end of the outer tube and supports the rigid rod and prevents it from moving forwards.