Recently, getting more reduction of energy consumption is attracting the attention in not only the society but also the industries. Therefore, the industries require pre-evaluation methods and production management methods to reduce energy consumption while maintaining productivity. On the other hand, in industry, defective products occur in the production process. The defective products affect lower productivity and waste of energy consumption, which affect will the specific energy consumption. However, research on evaluation method of the specific energy consumption considering the defective products has not conducted. Therefore, we propose a formula for quantitative evaluation of the specific energy consumption in production line considering the defective products. We also verify the validity of the proposed formula using a manufacturing system simulation. In a case study for a semiconductor manufacturing line, the specific energy consumption results by simulation and our proposed formula are compared. We confirmed that our proposed formula could accurately calculate the specific energy consumption. In addition, it was clarified that the specific energy consumption is increased by decreasing productivity due to the generation of defective products and by increasing the waste of energy consumption at periods in running states and idle states.