An organic light emitting display device comprising: - an organic light emitting diode layer provided at an active area (A/A) of a base substrate; - an encapsulation layer (170, 160) encapsulating the organic light emitting diode layer to protect the organic light emitting diode layer, the encapsulation layer (170, 160) comprises: an adhesive layer provided on the organic light emitting diode layer to cover upper and side surfaces of the organic light emitting diode layer, and an encapsulation substrate provided on the adhesive layer; - a signal pad provided on a pad area (P/A) of the base substrate; and - a cover layer provided between the signal pad and the adhesive layer, wherein the encapsulation substrate is provided to have different thicknesses at the active area (A/A) and outside the active area (A/A), the encapsulation substrate provided at the active area (A/A) has a thickness thinner than that of the encapsulation substrate provided outside the active area (A/A), wherein the cover layer includes a first portion next to the pad area (P/A) and a second portion next to the adhesive layer, the thickness of the first portion is lower than the thickness of the second portion so that the cover layer is inclined or curved from the adhesive layer to the pad area (P/A), and wherein the cover layer and the encapsulation substrate are provided to adjoin each other outside the active area (A/A) so that the side of the organic light emitting diode layer is not exposed through the adhesive layer. - an organic light emitting diode layer provided at an active area (A/A) of a base substrate; - an encapsulation layer (170, 160) encapsulating the organic light emitting diode layer to protect the organic light emitting diode layer, the encapsulation layer (170, 160) comprises: an adhesive layer provided on the organic light emitting diode layer to cover upper and side surfaces of the organic light emitting diode layer, and an encapsulation substrate provided on the adhesive layer; an adhesive layer provided on the organic light emitting diode layer to cover upper and side surfaces of the organic light emitting diode layer, and an encapsulation substrate provided on the adhesive layer; - a signal pad provided on a pad area (P/A) of the base substrate; and - a cover layer provided between the signal pad and the adhesive layer, wherein the encapsulation substrate is provided to have different thicknesses at the active area (A/A) and outside the active area (A/A), the encapsulation substrate provided at the active area (A/A) has a thickness thinner than that of the encapsulation substrate provided outside the active area (A/A), wherein the cover layer includes a first portion next to the pad area (P/A) and a second portion next to the adhesive layer, the thickness of the first portion is lower than the thickness of the second portion so that the cover layer is inclined or curved from the adhesive layer to the pad area (P/A), and wherein the cover layer and the encapsulation substrate are provided to adjoin each other outside the active area (A/A) so that the side of the organic light emitting diode layer is not exposed through the adhesive layer. wherein the encapsulation substrate is provided to have different thicknesses at the active area (A/A) and outside the active area (A/A), the encapsulation substrate provided at the active area (A/A) has a thickness thinner than that of the encapsulation substrate provided outside the active area (A/A), wherein the cover layer includes a first portion next to the pad area (P/A) and a second portion next to the adhesive layer, the thickness of the first portion is lower than the thickness of the second portion so that the cover layer is inclined or curved from the adhesive layer to the pad area (P/A), and wherein the cover layer and the encapsulation substrate are provided to adjoin each other outside the active area (A/A) so that the side of the organic light emitting diode layer is not exposed through the adhesive layer.