A method for fabricating an electronic device including a semiconductor memory includes: forming a variable resistance element over a substrate, the variable resistance element including a metal-containing layer and an MTJ (Magnetic Tunnel Junction) structure which is located over the metal-containing layer and includes a free layer having a variable magnetization direction, a pinned layer having a fixed magnetization direction and a tunnel barrier layer interposed between the free layer and the pinned layer; forming an initial spacer containing a metal over the variable resistance element; performing an oxidation process to transform the initial spacer into a middle spacer including an insulating metal oxide; and performing a treatment using a gas or plasma including nitrogen and hydrogen to transform the middle spacer produced by the oxidation process into a final spacer including an insulating metal nitride or an insulating metal oxynitride.