A method of manufacturing an OLED device is discussed. The method can include forming a gate electrode on a substrate; forming a gate insulation film on the substrate provided with the gate electrode; forming a channel layer, a source electrode and a drain electrode on the substrate provided with the gate insulation film; forming an organic light emitting diode which includes a first electrode connected to the drain electrode, an organic emission layer formed on the first electrode, and a second electrode formed on the organic emission layer; forming a passivation layer, which has a hydrogen content below 10%, on the substrate provided with the organic light emitting diode using an organic silicon compound; and forming a sealing layer on the substrate provided with the passivation layer.