A method and apparatus are disclosed for forming a drug coating layer capable of preventing breakage of elongated drug crystals on a surface of a balloon and maintaining the drug crystals in an appropriate shape in order to act on a living body. The method includes supplying a coating solution which contains the water-insoluble drug, a water-soluble additive, an organic solvent, and water to the surface of the balloon and evaporating the organic solvent and the water to form an additive layer containing the water-soluble additive and a protruding crystal having a tip end protruding from the additive layer, cutting a surplus portion protruding from the additive layer of the protruding crystal from a part surrounded by the additive layer and forming the part surrounded by the additive layer as the elongated body, and removing the cut-out surplus portion from the drug coating layer.
