After starting his career as a quality engineer at Arcelor-Mittal in 1980, Luc ROUSSEAU joined ELF Aquitaine's venture capital subsidiary in New York in 1981. He then held a number of positions of responsibility in the regional directorates for industry and research, notably as head of the technical control and nuclear safety divisions in the Nord Pas-de-Calais region from 1983 to 1987, and as head of the industrial development division in the Ile-de-France region from 1987 to 1989. From 1989 to 1995, he was deputy general secretary and then general secretary of the regional directorates for industry, research and the environment in the DARPMI at the Ministry of Industry. He was appointed deputy director of the office of the Minister of National Education (François Bayrou) and director of the office of the Secretary of State for Research (Elisabeth Dufourcq) in 1995. He became adviser to the Budget Director in 1996, and then chief of staff to the Minister for the Post Office, Telecommunications and Space (François Fillon) in 1997. He returned to the Ile-de-France regional directorate for industry, research and the environment in 1998, where he remained until 2002. He was then adviser to the Prime Minister (Jean-Pierre Raffarin) on industry, research, the environment and digital technology from 2002 to 2005. He was appointed Director General for Enterprise in 2005, then Director General for Competitiveness, Industry and Services in 2009. He became Vice-Chairman of the Conseil général de l'économie, de l'industrie, de l'énergie et des technologies (CGE) in 2012.