The work is devoted to the problem of scattering of monochromatic electromagnetic waves on heterogeneous dielectric inclusions of arbitrary shapes. For the numerical solution of the problem, the volume integral equation for the electric fleld in the region occupied by the inclusion is used. Discretization of this equation is carried out by Gaussian approximating functions. For such functions, the elements of the matrix of the discretized problem are calculated in explicit analytical forms. For a regular grid of approximating nodes, the matrix of the discretized problem proves to have the Toeplitz structure, and the matrix-vector product with such matrices can be carried out by the Fast Fourier Transform technique. The latter strongly accelerates the process of the iterative solution of the discretized problem. Electric flelds inside a spherical inclusion and its difierential cross-sections are calculated and compared with the exact (Mie) solution for various wave lengths of the incident fleld. Internal electric flelds and the difierential cross-sections of a cylindrical inclusion are calculated for the incident flelds of various directions and wave lengths.