In recent years, the importance of corporate activities with respect to the environment has been required, and the Mitsubishi Paper Mills Group is working to reduce total energy and fossil fuel energy consumption, making environmental efforts as an important issue. The power consumption of the compressor is said to account for a large percentage of the total power consumption at the manufacturing plant. In case of Hachinohe Mill, five compressors were constantly operating regardless of fluctuations in demand, so we needed to adjust the air pressure according to demand. Therefore, we decided to introduce the compressor number control system in order to reduce power consumption. In this paper, we report the energy-saving efforts and their effects by this control system.