This study compares the numerical analysis result of energy efficiency of a conventional pneumatic pressure booster and a pneumatic pressure booster with energy recovery. Pneumatic systems are widely used in industries such as automobile production lines, and many factories are now reducing the supply pressure in such systems to reduce energy consumption. Instead, pneumatic pressure boosters are used to increase air pressure, as the need for high pressure in some applications remains significant. However, these boosters waste energy when increasing pressure. So, we propose a pneumatic pressure booster with energy recovery, which recovers energy by reusing the compressed air that was used before. So, in this study, we conduct numerical analysis of a pressure booster with energy recovery.