A training computer program for simulation and elimination of instrument distortions is described. The program demonstrates the noise influence on the result of instrument distortion elimination. There is an opportunity to reduce noise effects introducing a priory information about the function to be found by filtration of restored function Fourier transform. But when spread function is wide, the distortion elimination becomes impossible. Some applications of the program to simulating and real experiments for educational and scientific purposes in spectroscopy are presented. The program as well as program description and user guide is accessible for everyone on Web site dfe3300.karelia.ru.