A semiconductor device includes a magnetic tunneling junction (MTJ) on a substrate, a first spacer on one side of the of the MTJ, a second spacer on another side of the MTJ, a first metal interconnection on the MTJ, and a liner adjacent to the first spacer, the second spacer, and the first metal interconnection. Preferably, each of a top surface of the MTJ and a bottom surface of the first metal interconnection includes a planar surface and two sidewalls of the first metal interconnection are aligned with two sidewalls of the MTJ.