Electroluminescent Display Device

An electroluminescent display device according to an exemplary embodiment of the present disclosure may include a substrate including an active area and a non-active area having a gate in panel (GIP) area outside the active area, an oxide thin film transistor disposed on the substrate in the GIP area, a passivation layer disposed on the oxide thin film transistor, a planarization layer disposed on the passivation layer, a buffer layer disposed on the passivation layer or the planarization layer in the GIP area and made of silicon nitride and a light emitting element disposed on the planarization layer and including an anode, a light emitting unit, and a cathode. As a result, by preventing hydrogen inflow into an oxide thin film transistor, characteristics and reliability of the thin film transistor can be improved.