The wet oxidation plant of the chemical enterprise CIBA-GEIGY AG, Plant Grenzach is investigated with regard to the effectiveness of the energy use. The basis is the ascertained energy status of the plant. With the help of the Pinch-method, whose advantages and limitations are underlined, the potential of the energy saving is determined. Over and above that, suggestions for the heat recovery measures are developed, whose amortization period is partly less than one year. For the assessment of the quality of the energy recovery or energy cost saving, respectively, and efficiency factor as a clear parameter is introduced.