An antenna module for a tablet personal computer is disclosed. The tablet personal computer comprises a main body and a housing with a screen, and the housing is pivotally connected to the main body. The tablet personal computer is capable of being switched to a tablet mode. The antenna module comprises an antenna device, a first magnetic element, and a second magnetic element. The antenna device is located concealably in the housing. The first magnetic element is coupled to an end of the antenna device. The second magnetic element is located in the main body. The second magnetic element is positioned corresponding to the first magnetic element in the tablet mode such that an end of the antenna device can be moved outside the housing due to a magnetic force between the first magnetic element and the second magnetic element.