A drug coating layer that prevents breakage of elongated drug crystals on a balloon surface while maintaining the drug crystals in an appropriate shape to act on the living body includes plural elongated bodies which are crystals of a water-insoluble drug each extending from the surface of the balloon at various lengths and angles, and a water-soluble additive layer provided in a space between an outer surface of an aggregate of the elongated bodies and the balloon surface to fill a space between the elongated bodies. The outer surface of the additive layer being located outside the aggregate, being uneven connecting a plurality of tip ends and side surfaces of the elongated bodies to each other. The tip ends of the elongated bodies slightly protrude from the additive layer, and the side surfaces and/or tip surfaces of the elongated body are exposed on the surface of the additive layer.