The energy levels of the valence and conduction band edges of various metal-phthalocyanines (MPcs) have been determined by using photoelectron emission and optical absorption measurements. Carrier behaviors at the interface of MPcs and a metallic material such as Au or Al have been investigated by measuring current-voltage characteristics of a metal/MPc/metal system with changing MPc. The current-voltage characteristics do not seem to be explained simply by the usual Schottky barrier considerations.