The increasing human needs recently and the dependence of the most of these needs on the energy make this sector more and more significant everyday. Should it known that how the other sectors are depended on the sub-sectors of the energy, it would be so easy to produce policy. Input-output analysis as a unit of economic activity researches the sectors and especially the exchanges of intermediate input between the sectors. So input-output analysis is a major instrument in terms of enabling to research the production and usage of the outputs of the productive sectors in economic scale, in sectoral level and quantatively. In the analysis made by using the input-output tables of Turkey Statistics Office for 2002 it was observed that energy sector has been a key sector recently. Also the relation of energy sector with the others was searched and the most input-output marketing sector of the energy sector was analyzed.