A method for fabricating an organic light emitting diode (OLED) display device, the method comprising: forming a plurality of first electrodes on a substrate; forming, sequentially, a first hole injection layer, a first hole transport layer, a first light emitting layer, a first electron transport layer, and a first buffer layer in a laminated manner on the substrate to cover first ones of the first electrodes through a first photo process; forming, sequentially, a second hole injection layer, a second hole transport layer, a second light emitting layer, a second electron transport layer, and a second buffer layer in a laminated manner on the substrate to cover second ones of the first electrodes through a second photo process; forming, sequentially, a third hole injection layer, a third hole transport layer, a third light emitting layer, a third electron transport layer, and a third buffer layer in a laminated manner on the substrate to cover third ones of the first electrodes through a third photo process; and forming a second electrode on the first, second, and third buffer layers (270a, 270b, 270c), wherein the first, second, and third buffer layers (270a, 270b, 270c) are made of a metal oxide, wherein the forming of the first hole injection layer, the first hole transport layer, the first light emitting layer, the first electron transport layer, and the first buffer layer comprises: depositing, sequentially, a thin film for a first hole injection layer, a thin film for a first hole transport layer, a first organic film, a thin film for a first electron transport layer, and a thin film for a first buffer layer on the substrate; applying a photosensitive resin to the entire surface of the substrate with the thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer deposited thereon to form a first photosensitive resin layer; exposing and developing the first photosensitive resin layer to form a first photosensitive resin pattern made of the photosensitive resin at a position where a first light emitting layer is to be formed; followed by selectively etching the thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer by using the first photosensitive resin pattern as a mask to form the first hole injection layer, the first hole transport layer, the first light emitting layer, the first electron transport layer, and the first buffer layer, which are formed of thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer, respectively, on the substrate. forming a plurality of first electrodes on a substrate; forming, sequentially, a first hole injection layer, a first hole transport layer, a first light emitting layer, a first electron transport layer, and a first buffer layer in a laminated manner on the substrate to cover first ones of the first electrodes through a first photo process; forming, sequentially, a second hole injection layer, a second hole transport layer, a second light emitting layer, a second electron transport layer, and a second buffer layer in a laminated manner on the substrate to cover second ones of the first electrodes through a second photo process; forming, sequentially, a third hole injection layer, a third hole transport layer, a third light emitting layer, a third electron transport layer, and a third buffer layer in a laminated manner on the substrate to cover third ones of the first electrodes through a third photo process; and forming a second electrode on the first, second, and third buffer layers (270a, 270b, 270c), wherein the first, second, and third buffer layers (270a, 270b, 270c) are made of a metal oxide, depositing, sequentially, a thin film for a first hole injection layer, a thin film for a first hole transport layer, a first organic film, a thin film for a first electron transport layer, and a thin film for a first buffer layer on the substrate; applying a photosensitive resin to the entire surface of the substrate with the thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer deposited thereon to form a first photosensitive resin layer; exposing and developing the first photosensitive resin layer to form a first photosensitive resin pattern made of the photosensitive resin at a position where a first light emitting layer is to be formed; followed by selectively etching the thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer by using the first photosensitive resin pattern as a mask to form the first hole injection layer, the first hole transport layer, the first light emitting layer, the first electron transport layer, and the first buffer layer, which are formed of thin film for a first hole injection layer, the thin film for a first hole transport layer, the first organic film, the thin film for a first electron transport layer, and the thin film for a first buffer layer, respectively, on the substrate.