This paper deals with a new mathematical formulation of methods for spectrochemical examination of irreversible O plus ne** minus (k)**f**,**h yields R and quasi-reversible O plus ne** minus (k)**f**,**h reversible reaction //k //b//,//h R simple charge transfer reactions on planar electrodes under conditions of semi-infinite linear diffusion making use of electrolysis under galvanostatic conditions. The principal equations relating to electrode potential and transition absorbances of the spectrally monitored species of O or R are derived. A possibility of determining the parameters of electrode process from measurements by transmission or reflection spectroscopy methods is presented.