An electronic device with an antenna device is provided. The electronic device include a radiator configured to transmit/receive an electromagnetic wave, a ground portion connected to one end of the radiator, the ground portion configured to conduct current such that a current corresponding to an opposite polarity of a current, which flows in the radiator, flowing in the ground portion, an expanded ground extending from a part of the ground portion, and a ground path extending from the ground portion to a region adjacent to the expanded ground so as to cause current to flow from the ground portion through a current path corresponding to the length of the radiator.