[en] The results of spatial distribution measurements of radiation intensities of spectral lines of hydrogen and light plasma impurities in the visible-light spectrum TO-1 tokamak are described. The method of electrochemical scanning with the help of rotating disk with notches was used. The experiments were carried out in the stable regime of discharge and in the regime with breakdown instability. In the stable regime absolute intensities of the spectral lines were measured. The concentration of radiating atoms and ions were calculated using the measured absolute intensities. Besides in order to determine the region in which the discharge appears in the cross section of the TO-1 chamber the spatial distributions of Hsub(β) neutral hydrogen spectral line in the initial stage of the discharge (0< t<1 mc) were obtained. In the unstable regime of the discharge the effect of instability on the time dependence of the spectral line intensities and on their spatial distributions was studied. The described spectroscopic method permitted to obtain the filament cross section distribution of C(3) carbide ion and neutral hydrogen atom concentrations in the stable discharge regime. The distributions obtained have the form of the graphs with a dip in the central part and a maximum close to the plasma periphere. The average filament cross section concentration values are the following: anti nsub(C(3))=8.2x10⁹ cm^-3 for the C(3) ion and anti nsub(0)=1.1x10¹⁰ cm^-3 for hydrogen atoms. The investigation into spatial distributions of the Hsub(β) line radiation in the initial stage of the filament formation showed that in the overwhelming majority of cases the discharge appears near the internal wall of the tokamak chamber