Explosive materials, are substances that contain a great amount of stored energy that can produce an explosion; a sudden expansion of the material after initiation, usually accompanied by the production of light, heat, sound, and pressure. The energy stored in an explosive material may be: chemical energy, such as nitroglycerine or grain dust, pressurised compressed gas, such as a gas cylinder or aerosol can, and nuclear, such as fissile isotopes of uranium-235 and plutonium-239. This book gathers current research in the study of explosive materials from authors around the globe, including the design of energetic materials; detection of post-blast traces of explosive materials using ambient mass spectrometry; tetraazapentalenes and benzofuroxans as explosive materials; and the effects of temperature and humidity on the characterisation of TNT explosive threats.