Automated three-channel polari-interferometer measurements of electron density distributions and magnetic fields in a laser plasma are presented. Each of the polari-interferometer channels, interferometric, Faraday, and “tenebral” (shadow), has been equipped with a CCD camera with the matrix (512 × 512). With special software for each of the channels, not only the distribution of the electron density on the basis of interferograms is obtained, but also the distributions of magnetic fields in plasma using the information from the Faraday and shadow images. The results of testing investigations obtained in the plasma experiment are the main part of this work.