Internal Explosion Engine The suggested internal explosion engine (further referred to as the Engine) is a heat-engine, using a kind of an explosive process – the process of explosion and detonation of an explosive - as a new principle of engine operation, featured by a high velocity of the process within the period of ≈ 10-5 sec., accompanied by the transition of potential energy of an explosive into the mechanical work of body motion propelled by detonation products. Technical results 1. The concentration of energy released by explosion of an explosive exceeds the concentration of energy released by combustion of conventional fuels by hundreds and thousands times. Hence a considerable improvement of all engine parameters, including overall power increase by 5 √ 10 times, boundless expansion of traction and power limits, independence of Engine operation from the environment. 2. The working medium is liquid and gaseous explosive chemical compounds and explosive mixtures along with the explosive endothermic compounds capable of rapid explosive transformations. To obtain an explosive with set detonation wave parameters explosives mixed with inert additives, which at the point of explosive transformation do not exceed acceptance limits of the resilience of the Engine parts material, can be used. Hence a wide variety of explosives, part of which can be used as the working medium for Engine operation. 3. Engine efficiency of about ≈ 50% depends on reaction exothermicity, composition and physicochemical properties of an explosive, as well as on geometric elements of Engine parts.