An electronic device including a semiconductor memory. The semiconductor memory may include a variable resistance element. The variable resistance element may include a first magnetic layer formed over a first auxiliary layer, a tunnel barrier layer formed over the first magnetic layer, a second magnetic layer formed over the tunnel barrier layer, a second auxiliary layer formed over the second magnetic layer, and a hard mask formed over the second auxiliary layer. Side surfaces of the first magnetic layer may be substantially aligned with side surfaces of the first auxiliary layer, and the side surfaces of the first magnetic layer may deviate from side surfaces of the hard mask.