The man, whose name was not reported, pleaded guilty to religious violence and to declaring a false identity to police at the scene, Radio France Internationale reported Wednesday.
Police said the man tore a niqab -- a garment that covers everything but the eyes -- off a woman he saw at a fairgrounds in Nantes in September. He was ordered to compensate the woman, who had to take three days off from work after the violence, RFI reported.
The man said he was trying to enforce the 2010 French law banning most face coverings in public.
"Ordinary citizens are not entitled to make the law themselves," the judgement said.
The man's lawyer said he apologized for his actions.