Two extremists stabbed 85 year old Fr Jacques Hamel to death inside the church at Saint-Etienne-du-Rouvray in July.
Prayers have not been said at the church in Normandy since.
General view of the church where a priest was killed in an attack in Saint Etienne du Rouvray, Normandy, France, Tuesday, July 26th 2016.
A purification ceremony was held before Mass as Catholics believe the murder has desecrated the church.
It's reported the two terrorists, Adel Kermiche and Abdel-Malik Petitjean, both 19, put knife marks into the altar, destroyed statues and wrapped rosary beads around statues.
They were shot dead by police who stormed the church some 45 minutes after they took a number of people hostage.
Fr Jacques Hamel was repeatedly stabbed by the pair, who forced another man to video the attack.
The priest shouted "Satan, get out of here, get out, Satan" during the attack.
In September Pope Francis said Fr Hamel was a martyr and already on his way to becoming a saint.
"He accepted his martyrdom there on the altar," the pontiff said.