Cleanrooms have high energy demands due to the constant climate conditions and high air purity they require. Because of rising energy costs, stricter political regulations, and the need to reduce CO2 emissions, energy efficiency in cleanrooms is becoming increasingly important. This presentation will introduce strategies for optimizing ventilation systems, innovative energy-saving options, and concepts for energy-efficient cleanroom design. Beyond economic benefits, improved energy efficiency also contributes to compliance with legal requirements and climate protection. Practical examples and modern technologies will demonstrate how companies can operate their cleanrooms more sustainably and cost-effectively.