An electronic device is provided. The electronic device includes a front plate disposed on a display, a back plate disposed on a back surface of the electronic device, a side member placed between the front plate and the back plate and forming an outer appearance of the electronic device together with the front plate and the back plate, and first, second, and third antenna modules including a plurality of conductive plates configured to transmit/receive a signal in a specified first frequency band and disposed between the front plate and the back plate so as to be adjacent to the side member. At least a portion of the side member is able to be used as an antenna of a signal in a specified second frequency band different from the specified first frequency band.