A balloon catheter provides pressure-contact to a wall of a lumen or a stent or a stent graft in the lumen without interrupting body fluid flow such as blood when the balloon is expanded in the lumen. The balloon catheter includes a single balloon arranged at a distal side of a catheter shaft, and three line-shaped portions extending outside the balloon over the entire length of the balloon along an axial direction of the catheter shaft at even intervals in a circumferential direction. The balloon is partially restricted from being expanded by the line-shaped portions and is expanded in a radial direction between the adjacent line-shaped portions to form three balloon expansion portions that are divided in the circumferential direction. Accordingly, gaps are formed between a lumen wall and outer circumferential faces of the balloon expansion portions so that blood or body fluid can be flown therethrough without being interrupted.
