An electronic device may include a semiconductor memory, and the semiconductor memory may include 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, wherein the free layer may include: a first sublayer having a damping constant of 0.1 or less; a second sublayer having a perpendicular magnetic anisotropy energy density ranging from 1.0×104 to 1.0×108 erg/cm3; and an insertion layer interposed between the first sublayer and the second sublayer.