An organic light emitting display (OLED) apparatus comprising: an anode including a reflection-anode ; a transparent cathode ; a first charge generation layer including a first N-type charge generation layer and a first P-type charge generation layer ; a second charge generation layer including a second N-type charge generation layer and a second P-type charge generation layer ; a first stack , which includes at least a first emission layer , disposed between the anode and the first charge generation layer ; a second stack , which includes at least a second emission layer , disposed between the first charge generation layer and the second charge generation layer ; and a third stack , which includes at least a third emission layer , disposed between the second charge generation layer and the transparent cathode , wherein, when 'T1' indicates a distance from an upper surface of the reflection-anode to an interface between the first N-type charge generation layer and the first P-type charge generation layer , 'T2' indicates a distance from the interface between the first N-type charge generation layer and the first P-type charge generation layer to an interface between the second N-type charge generation layer and the second P-type charge generation layer , and 'T3' indicates a distance from the interface between the second N-type charge generation layer and the second P-type charge generation layer to an upper surface of the transparent cathode , the 'T1', 'T2', and 'T3' satisfy the following Equation 1, T 3 > T 2 > T 1 characterized in that , assuming that the total thickness of T1, T2, and T3 is 100%, T1 is within a range from 10% to 20%, T2 is within a range from 30% to 40%, and T3 is within a range from 45% to 60%. an anode including a reflection-anode ; a transparent cathode ; a first charge generation layer including a first N-type charge generation layer and a first P-type charge generation layer ; a second charge generation layer including a second N-type charge generation layer and a second P-type charge generation layer ; a first stack , which includes at least a first emission layer , disposed between the anode and the first charge generation layer ; a second stack , which includes at least a second emission layer , disposed between the first charge generation layer and the second charge generation layer ; and a third stack , which includes at least a third emission layer , disposed between the second charge generation layer and the transparent cathode , wherein, when 'T1' indicates a distance from an upper surface of the reflection-anode to an interface between the first N-type charge generation layer and the first P-type charge generation layer , 'T2' indicates a distance from the interface between the first N-type charge generation layer and the first P-type charge generation layer to an interface between the second N-type charge generation layer and the second P-type charge generation layer , and 'T3' indicates a distance from the interface between the second N-type charge generation layer and the second P-type charge generation layer to an upper surface of the transparent cathode , the 'T1', 'T2', and 'T3' satisfy the following Equation 1, T 3 > T 2 > T 1 characterized in that , assuming that the total thickness of T1, T2, and T3 is 100%, T1 is within a range from 10% to 20%, T2 is within a range from 30% to 40%, and T3 is within a range from 45% to 60%. T1 is within a range from 10% to 20%, T2 is within a range from 30% to 40%, and T3 is within a range from 45% to 60%. <EOS>