After engineering studies at the Ecole Polytechnique and the Ecole Nationale Supérieure des Mines, Thierry Garnier held various positions in industrial companies, including Total and Usinor, before joining the Ministry of Industry, and then the Ministry of Foreign Affairs. In 1997, he joined Promodès as a hypermarket director trainee. He served as director of the Libourne hypermarket from 1998 to 1999, and then as regional director (for Continent Hypermarkets) of the Nord-Pas de Calais region in 1999 and 2000. In 2000, he was named Carrefour regional director for the greater Lille region, and then for the western Paris region. In December 2002, he was appointed Executive Director of Supermarkets - France. In February 2005, Thierry Garnier was appointed Managing Director for Supermarkets - France. On 23 January 2008, he was appointed to membership of the Management Board and Managing Director International (ex Europe).