The maintenance, at a shipyard in Toulon, took place over a period of six months, during which time significant modernization work was also performed, the company said.
"Scheduled refits are essential to return a ship to 'as new' condition," said Franck Bouffety, the DCNS Group's Charles de Gaulle program manager.
"This six-month period of intense contract maintenance and modernization is over. Other teams will now resume shore-based, day-to-day monitoring of the ship's systems and equipment."
DCNS said modernization work on the aircraft carrier included replacement of the ship's stabilization computer, overhaul of its propulsion system and installation of cabling for a planned IP network.
Intermediate work included cleaning and inspecting 25,000 engine room pipes, installing 6,000 new pipes and repainting a total area of 26,000 square yards.
The Charles de Gaulle was commissioned in 2001.