[en] The energy saving trend that was initiated few years ago in the French industry has amplified in 1999. The growth of industrial investments made in 1999 (+6.5%) has favored the mastery of energy consumptions (48 millions of tons of petroleum equivalent) in a context of sustained industrial growth (+2.6%). Between 1998 and 1999, the prices of the different energy sources has changed in a contrasted way: decay of coal prices, stability of natural gas and increase of petroleum products price with the exception of coke and petroleum. This book takes stock of the most recent and detailed results according to different approaches: type of energy sources, industrial sectors, regions.. (J.S.)