There is provided a liquid crystalline organic semiconductor material that can effectively develop electron conductive properties which a liquid crystal system inherently has. The liquid crystalline organic semiconductor material has both an isotropic phase and a smectic liquid crystal phase and comprises an electronically conductive liquid crystal material, wherein the concentration of an impurity in the liquid crystal material is controlled to a lower value than the critical concentration at which the electron conductivity of the liquid crystal material disappears or is significantly reduced rendering ion conduction dominant.