[Problem] To provide a heat spreader capable of removing heat from an element more efficiently and immediately than an existing one, and also capable of satisfactorily responding to further enhancement in performance and output of various apparatuses, and a method for efficiently manufacturing the same. [Solution] A heat spreader includes a Cu—Mo layer made of a Cu—Mo composite material and having an average thickness of less than or equal to 0.6 mm and a variation in thickness of less than or equal to 0.1 mm, and a Cu layer directly stacked on each of both surfaces thereof. A method for manufacturing the heat spreader includes planarizing a plate material of the Cu—Mo composite material constituting the Cu—Mo layer, and roll-bonding a Cu plate constituting the Cu layer to each of both surfaces thereof.