A portable terminal is provided. The portable terminal includes a flexible display element, a first antenna element disposed at a first region on the display element, a second antenna element disposed at a foldable second region on the display element to face the first region, and a switch element configured to selectively connect the second antenna element. When the display element is folded or rolled, the first and second antenna elements at least partially overlap each other, and the switch element disconnects the second antenna element. The portable terminal including the antenna device as described above may maintain a stable transmission/reception performance although it includes a flexible display element or a display assembly. When a plurality of antenna elements are provided, the portable terminal may implement a Multiple Input Multiple Output (MIMO) antenna device in a state where the display element is extended.