There is provided a method of fabricating a split-gate flash memory cell using a spacer oxidation process. An oxidation barrier layer is formed on a floating gate layer, and an opening to expose a portion of the floating gate layer is formed in the oxidation barrier layer. Subsequently, a spacer is formed on a sidewall of the opening with a material layer having insulation property by oxidizing, and an inter-gate oxide layer pattern between a floating gate and a control gate is formed in the opening while the spacer is oxidized by performing an oxidation process.