The desorption processes of β-lactogloblin fouled on a stainless steel surface during caustic and enzymatic cleanings were analyzed using the model in which the free energy of activation for the rate constant of the first-order kinetics was assumed to obey a Gaussian distribution. The model well expressed both processes. This would indicate that the β-lactogloblin molecules exist in various states and interact with the surface in various strengths corresponding to the states. The rate constant corresponding to the mean value of the free energy of activation was greater at the higher detergent concentrations for both the caustic and enzymatic cleanings.