From 1991 to 1996 Miller served with the Committee for External Relations of the Saint Petersburg Mayor's Office under Vladimir Putin. From 1996 to 1999 he was Director for Development and Investments of the Port of Saint Petersburg. From 1999 to 2000 he served as Director General of the Baltic Pipeline System. In 2000 he was appointed Deputy Minister of Energy of the Russian Federation, and since 2001 he has served as Chairman of the Management Committee of Gazprom. Prior to becoming the CEO of Gazprom, he had no experience in fossil fuels.