A method of manufacturing a metal oxide film includes injecting a reaction gas and metal precursors into a chamber, forming a first metal precursor film on a substrate in a plasma OFF state, forming a first sub-metal oxide film by oxidizing the first metal precursor film in a plasma ON state, and forming a second metal precursor film on the first sub-metal oxide film in the plasma OFF state, where the metal oxide film has an amorphous phase, a thickness of about 20 nanometer (nm) to about 130 nm, and a dielectric constant of about 10 to about 50.