The present state of the thermodynamics of ionic micellar systems is examined and the principal characteristics of these systems are discussed: The charge and activity coefficients of the micelles, the concentration of the monomers and the degree of binding of the counterions, and the dependence of the critical micelle formation concentration on the length of the hydrocarbon chain of the surfactant and on the added electrolytes. The thermodynamics of the micellar cell and the methods for the calculation of the electrostatic contribution to its energy are described. The bibliography includes 107 references.