A heat spreader (10) and a method for manufacturing the heat spreader are disclosed. The heat spreader includes a metal casing (12) and a wick structure (16) lines an inner surface of the metal casing. The metal casing defines therein a chamber (14) and includes an evaporating section (126) and a condensing section (127). The wick structure is in the form of metal foam and occupies a portion of the chamber. In one embodiment, the wick structure has a pore size gradually increasing from the evaporating section towards the condensing section of the metal casing. The heat spreader is manufactured by electrodepositing a layer of metal coating (70) on an outer surface of a metal foam framework (20). The metal coating becomes the metal casing and the metal foam framework becomes the wick structure.