The Differential Fourier Holography (DFH) gives an exact mathematical
solution of the inverse problem of diffraction in the Fraunhofer regime. After
the first publication [1] the Differential Fourier Holography was successfully
applied in many experiments to obtain amplitude and phase information about
two-dimensional (2D) images. In this article we demonstrate numerically the
possibility to apply the DFH also for investigation of unknown 3D Objects. The
first simulation is made for a double-spiral structure plus a line as a
reference object