A method of manufacturing an organic light-emitting device including a plurality of pixels using an organic solution spray apparatus, where each of the pixels comprises a plurality of sub-pixels having different colors, includes: preparing a substrate on which a plurality of sub-pixel regions is defined; generating a potential difference between a nozzle of the organic solution spray apparatus and the sub-pixel regions; spraying an organic solution from the nozzle of the organic solution spray apparatus to the sub-pixel regions; and forming an organic material layer by selectively depositing the organic solution to the sub-pixel regions using the potential difference between the nozzle and the sub-pixel regions.