The diffraction patterns of surface relief diffraction structures that consisted of two crossed identical superimposed gratings formed in As2S3 thin films by electron beam recording with subsequent chemical etching were studied. The angle between gratings with a grating period of 2 µm was varied between 2° and 90°. Additional diffraction gratings formed by a set of lines intersection nodes were considered for simulation of diffraction patterns. Diffraction structure composed of four identical crossed gratings was considered as combination of pairs of crossed gratings to calculate the diffraction pattern from it. A good agreement between experimental diffraction patterns and modeling ones was confirmed by the used method of calculation.