A method of manufacturing an organic light emitting display device, the method comprising: providing a substrate having a first width in a first direction and a second width in a second direction substantially perpendicular to the first direction, the first width being greater than the second width; defining a plurality of pixel regions on the substrate, each of the plurality of pixel regions being divided into a first region and a second region, each of the pixel regions including a first light emitting portion, a second light emitting portion, a third light emitting portion and a transmission portion configured to transmit external light arranged along the second direction; forming a first organic light emitting layer pattern extending in the first direction, the first organic light emitting layer pattern overlapping the first light emitting portions; forming a second organic light emitting layer pattern extending in the first direction, the second organic light emitting layer pattern overlapping the second light emitting portions; and forming a third organic light emitting layer pattern extending in the first direction, the third organic light emitting layer pattern overlapping the third light emitting portions, wherein the first light emitting portion, the second light emitting portion, and the third light emitting portion are formed in the first region of each of the pixel regions, and the transmission portion is disposed in the second region of each of the pixel regions, wherein forming the first organic light emitting layer pattern includes: arranging a mask structure over a deposition apparatus, the mask structure including a plurality of openings (221, 222, 223, 224, 225); emitting deposition particles from the deposition apparatus by heating the deposition apparatus; and transferring the substrate above the mask structure in the first direction. providing a substrate having a first width in a first direction and a second width in a second direction substantially perpendicular to the first direction, the first width being greater than the second width; defining a plurality of pixel regions on the substrate, each of the plurality of pixel regions being divided into a first region and a second region, each of the pixel regions including a first light emitting portion, a second light emitting portion, a third light emitting portion and a transmission portion configured to transmit external light arranged along the second direction; forming a first organic light emitting layer pattern extending in the first direction, the first organic light emitting layer pattern overlapping the first light emitting portions; forming a second organic light emitting layer pattern extending in the first direction, the second organic light emitting layer pattern overlapping the second light emitting portions; and forming a third organic light emitting layer pattern extending in the first direction, the third organic light emitting layer pattern overlapping the third light emitting portions, wherein the first light emitting portion, the second light emitting portion, and the third light emitting portion are formed in the first region of each of the pixel regions, and the transmission portion is disposed in the second region of each of the pixel regions, wherein forming the first organic light emitting layer pattern includes: arranging a mask structure over a deposition apparatus, the mask structure including a plurality of openings (221, 222, 223, 224, 225); emitting deposition particles from the deposition apparatus by heating the deposition apparatus; and transferring the substrate above the mask structure in the first direction. arranging a mask structure over a deposition apparatus, the mask structure including a plurality of openings (221, 222, 223, 224, 225); emitting deposition particles from the deposition apparatus by heating the deposition apparatus; and transferring the substrate above the mask structure in the first direction.