A method of manufacturing an organic light emitting display apparatus, the method includes loading a substrate on a moving unit, determining an angle formed between a side of the substrate and an opening in a patterning slit sheet, rotating the patterning slit sheet by two X motors so that the side of the substrate and the opening in a patterning slit sheet extend along the same direction and forming a layer on the substrate while conveying the substrate on the moving unit in the first direction in a chamber. The patterning slit sheet moves along a direction perpendicular to the first direction during the forming the layer on the substrate so that a deposition layer having a linear pattern that extends along the first direction is formed on the substrate.