Abstract:Background. The aim of the work is to study an inverse problem of tensor reconstruction of a multi-sectional diaphragm in a rectangular waveguide by the transmission or reflection coefficients. Material and methods. The problem is considered as an inverse problem of electrodynamics, it is presented as a boundary value problem for Maxwell's equations; it was applied the theory of boundary value problems for Maxwell's equations, the theory of approximate methods for solving nonlinear systems. Results. The author has developed a numerical-analytical solution for the inverse problem of tensor reconstruction of a multi-sectional diaphragm in a rectangular waveguide by the transmission or reflection coefficients. Conclusions. The obtained results can be used for determination of electromagnetic characteristics of anisotropic composite materials.