In a heat spreading module for a portable electronic device configured such that a heat pipe is attached along a metal plate with which a heating element is brought into close contact, and heat of a heated region of the metal plate with which the heating element is brought into close contact is transferred to a place on the metal plate apart from the heated region by the heat pipe, the heat pipe is configured such that a container is formed of a pipe, a portion of the container arranged on the heated region is a heated portion, and a portion of the container apart from the heated region is a heat dissipation portion that dissipates heat to the metal plate, and the heated portion is formed in a flat shape, and the heat dissipation portion is formed to be thicker than the heated portion having the flat shape.