An antenna structure includes a first radiation element, a second radiation element, a third radiation element, a fourth radiation element, a fifth radiation element, and a nonconductive support element. The first radiation element has a feeding point. The second radiation element is coupled to the first radiation element. The third radiation element is coupled to a ground voltage and adjacent to the first radiation element. The fourth radiation element is coupled to the first radiation element. The fifth radiation element is coupled to the ground voltage and adjacent to the second radiation element. The first radiation element, the second radiation element, the third radiation element, and the fourth radiation element are at least partially surrounded by the fifth radiation element. The first radiation element, the second radiation element, the third radiation element, the fourth radiation element, and the fifth radiation element are disposed on the nonconductive support element.