A balloon coating method for forming a coating layer containing a water-insoluble drug on the outer surface of a balloon of a balloon catheter. The method includes applying a first rotation force to the balloon catheter proximal to the balloon of the balloon catheter and applying a second rotation force to the balloon catheter distal to the balloon of the balloon catheter. The first rotation speed is the same as the second rotation speed. The method includes applying a coating solution containing the drug to the outer surface of the balloon from a dispensing tube while gradually moving the dispensing tube in the axial direction and simultaneously applying the first and second rotation forces to rotate the balloon catheter around the longitudinal axis of the balloon catheter.
