An electronic device according to an embodiment may include a housing comprising: an outer portion defining at least a portion of an exterior of the electronic device and comprising a first conductive material, an inner portion comprising a second conductive material having a first melting point different from that of the first conductive material and at least partially defining a space for receiving multiple electronic components arranged inside the electronic device, and a middle portion comprising a third conductive material having a second melting point and an injection molded insulator, wherein the third conductive material of the middle portion and the first conductive material of the outer portion are coupled to form a concave-convex structure, a difference between the first melting point and the second melting point is in a first range, and the third conductive material of the middle portion is electrically connected to the second conductive material of the inner portion. Various other embodiments identified through the specification are possible.