Abstract: A thin film deposition method and a method of fabricating an electronic device using the same are disclosed. The thin film deposition method may include preparing a substrate structure having a pattern portion including a hole, adsorbing a reaction inhibitor to inside and outside of the hole in the substrate structure, wherein an adsorption density of the reaction inhibitor may be lower in the inside than the outside, and depositing a metal layer on the inside and outside the hole by an atomic layer deposition (ALD) process, wherein a deposition rate of the depositing may vary depending on regions by the reaction inhibitor, and wherein the reaction inhibitor may include a metal atom and a ligand for reaction inhibition bonded to the metal atom, and the metal atom may remain on the substrate structure in the depositing the metal layer.