The defensive energy-saving glass is made by sandwiching polycarbonate and NF membrane between two pieces of glasses. Since polycarbonate has excellent impact resistance and compressive strength properties, therefore, by applying it with Dresden glass, it can further reinforce the glass against tapping without fragmentation and intrusion. The glass was carefully chosen to have higher degree of hardness than that of polycarbonate to protect against scratching. Moreover, NF membrane also provides the energy-saving function, making Dresden glass a perfect integration of protection and energy-saving product.