The book presents the method of thermodynamic Green Functions applied to the problems of electrochemistry. The basic theorems and their derivations are found at the didactic level which requires, however, a knowledge of the principles of quantum mechanics and statistical physics. The book is mainly based on the results of papers published during the last fifteen years by its authors and their coworkers from the Department of Theoretical Chemistry and the Department of Solid State Physics of the University ofL6di (poland) within the context of the results reported in literature. Although the Green Functions Method has become very popular in solid state physics, there are almost no applications of this technique to electrochemistry. The only papers where the Green Functions Method is applied to the molten salts and liquid mercury theory are the precursory works published by Professor S. G. Davison and his coworkers from the Waterloo University (Canada) in the early eighties. We hope that the present book can fill this gap in the electrochemical literature.