A system of the kinetic equations of the material balance for the concentrations of surfactant monomers and micelles in a micellar nonionic surfactant solution was formulated. The equilibrium state of a materially isolated micellar solution was analyzed. The system of the kinetic equations of the material balance of a micellar solution was solved. The total time of the establishment of equilibrium in a micellar solution was determined. It was shown that this time increases or (typically) decreases with an increase in micelle concentration, depending on the degree of micellization.