An electronic device includes an inner case, at least one radiator disposed on a surface of the inner case, and an outer case integrally formed on the surface of the inner case, in which the outer case at least partially conceals the radiator. A method for manufacturing a housing of an electronic device includes molding an inner member by injecting resin into an injection mold, extracting the inner member from the mold, forming or disposing a conductive pattern on a surface of the inner member, inserting the inner member comprising the conductive pattern into another injection mold, and molding a periphery member that encloses at least a portion of the inner member by injecting resin to the other injection mold, wherein rigidity or stiffness of the inner member is higher than that of the periphery member. Other embodiments are also disclosed.