An electronic device is provided. The electronic device includes a front plate, a rear plate facing away the front plate, a side member disposed to surround a space defined between the front plate and the rear plate, wherein the side member is coupled to the front plate and the rear plate to define a housing, wherein the side member is at least partially made of a metallic material, a polymer structure located in the space, and a display received in the space to be viewable through the front plat. The rear plate may be seated on the second surface.