"This is an unprecedented rhythm and intensity of strikes," air force chief André Lanata told a parliamentary committee in a hearing last month whose minutes have just been made public.
Twelve French jet fighters are operating out of bases in Jordan and the United Arab Emirates as part of the US-led coalition against IS.
They have been reinforced by the 24 fighter planes during the three missions carried out by the Charles De Gaulle aircraft carrier.
The French effort makes up five percent of the coalition's strikes.
Most of them have flown out of Jordan, which is nearer to northern Iraq, where the vast majority of the raids have taken place.
French pilots have flown more than 10,000 hours in 2,300 sorties from the Jordanian base, according to Lanata.
Buying munitions from US
Since 2015 the air force's supply of munitions ran low, forcing it to seek help from allies in Europe and from Canada, General Jean Rondel told a separate Senate committee in October.
"Then we bought them abroad, from the US, because we have no more production capacity," he said.
Until this summer France was using both Rafale and Mirage 2000 fighter planes.
Since then the Rafales have replaced the Mirages because they can fly greater distances and are less likely to run out of fuel over hostile territory.