An antenna module includes a main body, a baseboard, and a ground portion. The main body is made of conductive material. The baseboard is received in the main body and includes a feed point. One end of the feed point is electrically connected to the main body. Another end of the feed point feeds current to the main body. The ground portion is grounded and defines a space. The baseboard is spaced from the main body to form a first gap therebetween. The ground portion is positioned in the first gap to electrically connect the baseboard to the main body and an area of the first gap corresponding to the space forms a second gap.