We have developed a thin film multi layer as encapsulation method for OLED. The characteristics of the OLED encapsulated with thin film multi layer showed the similar OLED with metal cap encapsulation. The I-V-L test of OLED panels with thin film multi layer showed that the brightness is 1000 cd/m(2) with the efficiency of 7.6lm/W at the 7 V and it took more than 2000 h for the brightness to fall from 1000 to 500 cd/m(2). This result shows that the device with thin film multi layer has similar level of brightness and efficiency and more than 95% of lifetime compared to device with metal can encapsulation. Thus, we can confirm that thin film multi layer has an effect as encapsulation process to protect organic light emitting device. Also, thin film multi layer for the protection of organic light emitting device simplifies passivation process, makes less than 0.8 mm thick device and is also applicable to wide and flexible display. (C) 2004 Published by Elsevier B.V.