The electric conductivity of metal-p-quaterphenyl-metal thin polycrystalline layers sandwieh struetures have been investigated asa function of voltage, thickness, and temperature. The films which ranged in thickness from 0.9 to 1.6 pm were measured in the temperatute range of 100--370 K. The experimental data may be explained by space charge effects with contribution of Riehardson--Schottky meehanism or in terms of injeetion modified by space eharge effects.