We propose a novel approach for the study of rheological properties of silica nanoparticle monolayers at the air-water interface. The layers are deformed by indenting and raising a titanium cone. The surface pressure variations in these down-up cycles are recorded and analysed. The oscillation amplitude of surface pressure d results from the tensile deformation of the particle layer. d and the relaxation time are strongly dependent on the adsorption energy of particles at the interface, thereby significantly changing the particle hydrophobicity. The results provide a deeper insight into the viscoelastic behaviour of particle layer, suggesting that the proposed method can be utilized for the rheological study of the layers of this kind.