Mixed Langmuir-Blodgett films of behenic acid (docosanoic acid) and glucose oxidase have been elaborated. The resulting films transferred on muscovite have been studied by scanning force microscopy. The general organization of the mixed film has been observed. Lateral force microscopy coupled with topographic data obtained with the contact mode, and a selective solubilization process have made possible the distinction between enzyme and behenic acid domains. The general organization of the mixed film may be described as quasi circular domains of glucose oxidase surrounded by a behenic acid monolayer. Both of them are organized on a sublayer of glucose oxidase molecules adsorbed on muscovite.