Interface studies of tris-(8-hydroxyquinoline) aluminum (Alq3)/LiF/Al were carried out with high-resolution electron-energy-loss spectroscopy. With LiF on Alq3 or Al on LiF, no significant changes in intensity were observed for the loss peak related to the Li-F stretch mode. However, the deposition of less than one monolayer of Al on Alq3/LiF resulted in a strong attenuation of the LiF-loss peak, providing a direct evidence of LiF dissociation in the coexistence of Alq3 and Al with LiF. On the other hand, the LiF-loss peak remained almost unchanged when Al was deposited on poly (9,9-dioctyl-fluorene)/LiF.