An antenna device is provided in the disclosure. The antenna device includes a metal component, a signal cable, and a grounding component. The metal component includes a slot. The slot includes an open end and a closed end, and the open end forms an opening at a side of the metal component. The signal cable includes a signal portion and a grounding portion. The signal cable is disposed such that a projection of the signal portion is partially overlapped with the opening. The grounding portion is electrically connected to the metal component through the grounding component.