The objective of this study was to examine the energy conservation measures conducted in designated factories over the past 10 years. The number of measures implemented, the energy-saving from the measures, the investment’s cost-effectiveness for each sector, and the level of energy conservation measures were utilized to propose policy recommendations to related government agencies. Data were obtained from designated factories that submitted their energy management report over the past 10 years (2010 – 2019), encompassing all industrial sectors. From the research, it was found that the Non-Metallic group had the highest Energy Intensity (EI), and the Paper group had an EI value that increased significantly. Analysis of energy conservation measures results was conducted, with the number of measures, the energy-saving from the measures, and the cost-effectiveness taken into account. The finding indicated that the most common measure was “Changing from fluorescent lamps (FL) to light-emitting diode (LED) lamps measure” for all. The measure with the highest amount of energy-saving was “Improving the efficiency of the production process measure” for a total of 3,324,943,687.80 MJ for the Non-Metallic group and “Switching to another type of fuel measure” for a total of 744,704,146 MJ for Paper group. The measure with the fastest payback period was “Measures to replacement of other lamps” with an average payback period of 0.01 years for the Non-Metallic group and “Changing the propeller size measure” with an average payback period of 0.02 years for the Paper group. Policy recommendations for the Department of Alternative Energy Development and Efficiency, Ministry of Energy include a recommendation to continuously promote the transition from fluorescent lamps to LED lamps, especially in those industrial sectors that have not implemented the measure. The efficiency of LED lamps should be performed and new energy efficiency standards should be regularly renewed at an appropriate time interval. Regulations concerning energy management should also be amended to, instead of prioritizing significant energy-consuming equipment, consider the overall production processes in various industrial sectors. Further analysis on the data concerning using Demand Controller to control the operation measure, changing the propeller size measure, using a high-efficiency motor measure and boiler replacement measure with fast average payback period but not implemented every year nor widely, should be performed and used as a guide toward more widespread implementation of such measures.