A large photocurrent multiplication reaching 130 000‐fold at room temperature has been observed in naphthalene tetracarboxylic anhydride (NTCDA) film sandwiched between metal electrodes. This phenomenon is reasonably interpreted in terms of the tunneling injection of electrons from a metal electrode, which is triggered by the accumulation of photogenerated trapped holes near the metal/organic interface. The combination of an ultrathin NTCDA film with another photoconductive pigment film in a layered structure allowed us to fabricate a photocurrent multiplication device with the desired spectral response. ©1996 American Institute of Physics.