An organic light emitting device, efficacy and lifetime of which are improved by forming a blue light emitting layer disposed over respective pixels in common as a double layer structure, includes a substrate divided into and defined by first to third pixels, a first electrode disposed on the TFT substrate and a second electrode facing the first electrode, the second electrode being spaced from the first electrode, a first light emitting layer and a second light emitting layer disposed in the first pixel and in the second pixel, respectively, between the first electrode and the second electrode, a sub-light emitting layer and a third light emitting layer disposed over the first to third pixels in this order on the first light emitting layer and the second light emitting layer.