This work is directed to the elucidation of the peculiarities of fullerene C₆₀ interactions with bovine serum albumin (BSA) in mixed layers at the water-air interface. To this aim, the dilational surface elasticity was measured as a function of surface pressure and surface age and optical methods together with the atomic force microscopy (AFM) were applied. The dependencies of the dilational dynamic surface elasticity of the mixed C₆₀/BSA layers on the surface pressure have two local maxima indicating a conformational transition in the layer. At low surface pressures (region of the first maximum) the surface properties are determined mainly by the protein, while in the second region of relatively high surface pressures the contribution of the fullerene is more important. The AFM images show that both C₆₀ layers and mixed C₆₀/BSA layers contain separate large fullerene aggregates with the length in Z-directions of up to 100 nm but the morphology of the regions between these aggregates differs for the two systems. The mixed layer contains some patches of a network of almost merged fullerene/protein aggregates with a length in Z-direction not longer than about 20 nm. The formation and the subsequent reorganization of the network lead to non-monotonic kinetic dependences of the dynamic surface elasticity in the course of protein penetration into the fullerene layer. The obtained results show strong interactions between the components in the surface layer and thereby can change the toxicity of the fullerene.