The purpose of the present study is to estimate, by cointegration, the long-run elasticities, mainly the price and income, of the demand for electric energy in the three consumption categories: residential, commercial and industrial. The obtained results support the premise that the income elasticity should be near or beyond a unity, and that the magnitude of price-elasticity should be lower one, in terms of absolute value. Predictions for the electric energy consumption for the 2001-2005 period are also made