The present invention provides a low-profile balloon catheter capable of providing pressure-contact to a wall of a lumen or a stent or a stent graft in the lumen without causing flow of body fluid such as blood to be interrupted when the balloon is expanded in the lumen. The present balloon catheter 1 includes a single balloon 3 arranged at a distal side of a catheter shaft 2, and three line-shaped portions 11 extending outside the balloon over the entire length of the balloon along an axial direction of the catheter shaft as being arranged 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 be formed into three balloon expansion portions 3a to 3c that are divided in the circumferential direction. Accordingly, gaps 14a to 14c are formed between a lumen wall 13 and outer circumferential faces of the balloon expansion portions so that blood or body fluid can be flown therethrough without being interrupted.
