The defence industry congregates more than 4 000 companies, a turnover of nearly 15 billion euros and about 165 000 jobs. It is a driver in economic competitiveness. It is a flagship of France on international markets with its exported production varying between 25 and 40% from year to year. These figures attest the importance of the defence industry in the French economy and in its diplomacy. Over the last fifteen years, new materials have been added to the range of equipment for our armed forces. Meanwhile, the defence area has broadened, and boundaries between defence and security have gradually faded. The general concept of defence industry has arisen from this evolution. The defence industry study group acts as a relay network to publicise the concept, its dimensions and its attendant issues so that its role in our political, economic and diplomatic initiatives can be fully fathomed.