An organic electroluminescent device, which, on a substrate, has a plurality of first electrodes, and a second electrode opposing the plurality of first electrodes. The organic electroluminescent device also including a light-emitting functional layer between the second electrode and one of the first electrodes and a buffering layer that covers the second electrode. The buffering layer having a side end portion with an angle equal to or less than 30°. The organic electroluminescent device further including a gas barrier layer that covers the buffering layer.