A method for fabricating semiconductor device includes the steps of: forming a magnetic tunneling junction (MTJ) stack on a substrate; forming a top electrode on the MTJ stack; performing a first patterning process to remove the MTJ stack for forming a first MTJ; forming a first inter-metal dielectric (IMD) layer around the first MTJ; and performing a second patterning process to remove the first MTJ for forming a second MTJ and a third MTJ.