A planar inverted-F antenna for use in a wireless network device comprises a connecting member and two radiators. The connecting member has at least one input end and at least one ground end. Each radiator has a first end portion perpendicularly connected to one of the two ends of the connecting member, and the two radiators are parallel and correspond in shape to each other. Each radiator further has an L-shaped notch and thus forms a barb. A second end portion of each radiator is bent to form an engaging end which is generally parallel to the connecting member and configured to fasten with a substrate of the wireless network device.