This paper demonstrates an econometric estimation of substitution elasticities of a nested constant elasticity of substitution production function (CES) between capital, energy and labour for the West German industry. In the last few years CES production functions have become more important in economic modelling, especially for applied general equilibrium models where CES production functions are an important building stone. In the literature, different results of estimated elasticities can be found. This paper investigates three different approaches for nested CES production functions and their estimated substitution elasticities. Capital, energy and labour are estimated as substitutes for the West German industry in the long run.