A small congregation in white hard hats has attended mass at Notre Dame Cathedral in Paris, the first service since fire devastated the Gothic landmark two months ago.
Church leaders are keen to show life goes on at the cathedral as donations for rebuilding trickle in.
Less than 10 per cent of the 850 million euros ($A1.4 billion) pledged by billionaires, business leaders and others has been received so far, the French government said.
The mass, which commemorates the cathedral's consecration as a place of worship, was held in a side-chapel left undamaged by the April 15 fire, with attendance limited to about 30 people wearing protective headgear.
Priests in ceremonial garb of white robes and yellow stoles briefly parted with their hard hats during the communion.
"It is with much emotion that we are here to celebrate the consecration of the cathedral," said Paris's archbishop Michel Aupetit, who led the service.
"It is a message of hope and thanks to all those who were moved by what happened to this cathedral," he added, acknowledging afterwards it was "a bit strange" to celebrate mass with a helmet.
The service was broadcast live on a religious TV channel that showed poignant images of the blue sky through the collapsed roof, and black rubble still clogging the building.
Australian Associated Press