First of all, this paper analyzes the effects of structural changes and improvements in energy intensities for the energy consumption of the manufacturing sector in Korea using energy elasticity method. Then, we forecasted mid-term energy demand with the 8scenarios. Major findings are that the rapid increase of energy consumption in the manufacturing sector is mainly due to production increase and structural change to the energy intensive one. This trend intensified from the last of the 1980's, because of expansion of petrochemical and cement industries. The forecasting estimated from the past 24 year trends and intensity improvement assumption shows similar figures to the actual ones. It can be sail that the manufacturing sector in Korea is changing to the energy-efficient structure from the mid 1990's. According to the forecasting, energy demand in year 2001 will be 1.4 times larger than that in 1995. This method could be used for a good standard in verifying the validity of other prospects.