An electronic device including an antenna implements a method for recognizing whether a case is attached to the electronic device by using the antenna. The electronic device is configured to attach to an electronic device cover which may include: a cover part configured to surround at least a portion of a housing of the electronic device or form at least a portion of a rear plate of the electronic device; and at least one conductive member configured to, when the electronic device is attached to the cover part, at least partially overlap at least two antennas arranged inside the electronic device and spaced apart from each other. A coupling between at least one of the at least two antennas and the at least one conductive member may be used to recognize whether the electronic device is attached to the cover part.