A lens module includes a barrel, a first lens, an annular retaining member and three driving devices. The retaining member is arranged in the barrel. The driving devices are arranged on the retaining member. Each of the driving devices has a base attached on the retaining member, a plurality of first electrodes formed on the base and a comb-shaped carrier. The carrier has a beam attached on the base and a plurality of second electrodes extending from the beam and suspended above the first electrodes at a first position. The first lens is carried by the second electrodes. When a first voltage is applied on the first electrodes and a second voltage is applied on the second electrodes, an electrostatic force is generated between the first electrodes and the second electrodes, and the second electrodes are moved down, such that the first lens is brought to a second position.