A heat sink, including a base section in contact with a heating unit, and a heat-dissipating section for dissipating heat received from the heating unit by the base section, in which the base section includes at least one metal layer, and the heat-dissipating section includes a laminate prepared by laminating a metal layer and a graphite layer through an adhesive layer formed by using a composition containing a polyvinyl acetal resin, or a heat sink for dissipating heat from a heating unit, in which the heat sink includes a laminate prepared by laminating a metal layer and a graphite layer through an adhesive layer formed by using a composition containing a polyvinyl acetal resin, and is arranged so as to cover the heating unit.