The present invention relates to an organic light emitting device and a manufacturing method thereof. The present invention discloses an organic light emitting device including: a plurality of scanning signal lines; a first and second contact assistant; a plurality of data lines crossing the scanning signal lines; a driving voltage line; and a first pixel, a second pixel, and a third pixel alternately arranged, wherein each pixel includes: a switching transistor, a driving transistor including an output terminal, a pixel electrode connected to the output terminal, the pixel electrode including at least two layers including a transflective electrode, an organic light emitting member arranged on the pixel electrode, and a common electrode arranged on the organic light emitting member, wherein the first pixel further includes a supplementary member arranged on the pixel electrode, and wherein the first and second contact assistants include the same material as the supplementary member.