Even 20 years ago, it was suggested that the electro motive force is generated in the MIM-structured LB ultra-thin film element. It is known that the current-voltage curve does not pass the origin. In addition, the reason for the generation of voltage is considered to be the chemical reaction taking place in the LB film etc.. In this paper, it is proposed that with chemical reaction it may be difficult to explain the fact that the same phenomenon of voltage generation and electric properties can be investigated for the sample fabricated 6 - 7 years ago and the new sample. Thus, it is considered to be necessary to clarify the characteristics of voltage generation with a point of view of utilization or removal of voltage generated.