Beryllium (Be) is a lightweight metal with unique chemical and physical properties. It is stiff, resistant to corrosion, a good conductor of electricity and heat, and dimensionally stable during extreme temperature changes. These properties have made it desirable for many commercial and defense applications, such as aircraft and satellite structures, high-speed electronic circuitry, nuclear applications, and precision instruments. It has also been used in dental appliances, golf clubs, non-sparking tools, and wheelchairs. This book discusses the physicochemical properties, applications and safety concerns of beryllium.