Two-dimensional effective point spread function for the ultraviolet telescope mounted onboard the space astrophysical station "Astron" was reconstructed from the data of specially arranged observations of the moon and Earth's disks illuminated by the Sun by solving the relevant inverse problem. The range of the reconstructed function variation is about 1013. Several characteristic regions of the function variation have been revealed as caused by the telescope design peculiarities. The results are used for interpretation of the data of the upper Earth's atmosphere investigation.