It is shown on the example of computation of material balance of waste gas processing from chlorosilane production that usage of program product Excel from Microsoft Office makes it possible to calculate material balance of technological processes with less intensity, compute without effort large numbers of variants and therefore to choose the optimal variant for realization of technological processes. Features of balance schemes, produced in Excel are considered. Also, the results of automated calculation of physicochemical properties (hardness, toughness, thermal capacity surface tension and thermal conductivity) of material flows, completed in Excel and joinked with balance scheme are presented.