The robbery took place in the city's chic Avenue Montaigne, home to many luxury stores, which is just off the Champs-Elysees.
The robbery was confirmed by staff at the shop, who gave no details about what was stolen.
A police source, however, said the stolen goods were valued at “several hundreds of thousands of euros”.
“I saw some guys come out, wearing masks,” a witness told AFP on condition of anonymity.
“Without thinking, I put myself in front of their car. Then I saw one of them was carrying a gun so I left.”
Another Chanel boutique on the same street was hit by thieves last month who rammed the storefront with a 4×4 car in the early hours of the morning.
In that incident, the robbers escaped by scooter after stealing several luxury handbags, police said.