<p>PURPOSE: A heat sink structure of a generator for an automobile is provided to improve exothermic performance of the heat sink by expanding an atmosphere contact area of a heat radiation fin by extending a domain of a negative diode lead hole into a border area of the heat radiation fin. CONSTITUTION: Positive diode holes(331) and negative diode lead holes(333) are alternately installed in the circumference of a heat sink(33). A heat radiation fin(335) shares a boundary face with the negative diode lead hole in order to secure an atmosphere contact area. A heat dissipation hole(337) is formed in the location faced around the negative diode lead hole centering around the positive diode hole.</p>
