A balloon catheter includes a balloon. The balloon allows restraint-free arrangement of an irregular region on the balloon for quickly inserting the balloon into a stenosis or stricture or an obstructed part while the balloon is in a contracted state, and allows for securely fixing the balloon within the stenosis or stricture or the obstructed part while the balloon is in an expanded state. The balloon can be easily produced, and can be folded without restraint (without requiring differentiation between the irregular region and the rest of the balloon). The balloon includes a base portion having an irregular region on its surface, and a coating agent coating the surface of the base portion. When the balloon is not expanded, the surface of the balloon is smooth and flat； and while the balloon is in an expanded state, the surface of the balloon is irregular.
