Speaking exclusively to Express.co.uk, the Pope's spokesman said the pontiff was aware of threats made by ISIS against him but was "not afraid" of the sick Daesh fighters.
He said Pope Francis is also refusing to have alterations made to his Popemobile to protect himself during this year's Christmas Day message.
The Pope has been advised by police to beef up security in the wake of fresh threats but has refused to change his famously relaxed style of leadership in response to the jihadi group.
It comes as the fanatical Islamist organisation has released a string of propaganda videos threatening to launch Paris-style attacks on the Italian capital.
Pope Francis is considered a specific target as head of the Catholic church.
His recent recent condemnation of the atrocities in the French capital are also likely to mark him as someone at high-risk of attack.
But the defiant pontiff will not be cowed by death threats from the barbaric terror group.
Pope Francis is not afraid
"He is not afraid," his spokesman said, adding that Pope Francis "knows everything [about the threat from ISIS] but he doesn't want to lose the contact with the people".
Father Ciro Benedettini told Express.co.uk the church was aware of videos produced by ISIS, but added: "There is no specific threat apart from those coming from the IS or Daesh on the web.
"There are some pictures of the black flag [of ISIS] on St Peter's.
"It could be a real threat, maybe it is something just to show how powerful they are and that is really easy to do a post like that."
Asked how the Vatican was responding to the threat, the deputy media director said: "There are special measures, you see the presence of the police everywhere, also of the Italian soldiers with guns.
"I don't think there will be special [security measures] for Christmas apart from what is already there."
The Argentine pontiff has flatly refused to wear protective clothing or use an armoured vehicle during his sermons or trips abroad, Father Benedettini said.
He added: "The Pope doesn't want to wear the bulletproof vest.
"It is understandable in his position he doesn't want to wear a bulletproof vest - that is ridiculous to go on the altar in one.
"It is understandable obviously that the police and the gendarmerie would like the Pope to be more protected, but that is something that can't be changed.
"He is not afraid - you have seen that he has gone to Africa, he went to the Central African Republic which everybody asked him to avoid.
"He went there, he didn't have any danger, he was able to invite the imam to come with him in the Popemobile.
"He knows everything [about the alleged threat] obviously but he is not very concerned."
Rome has long been touted as a potential target for the jihadi death cult.
The latest ISIS propaganda video shows computer-generated tanks advancing on a crumbling Colosseum, while a deserted Vatican City is bathed in an orange light and accompanied by chilling music.
The narrator then promises a final battle between "believers" and "crusaders" with ISIS taking over Rome, destroying crucifixes and taking Christian women as slaves.
It follows just days after hackers claiming to be from ISIS posted footage of hostages being beheaded on a church website.
The hackers said ISIS would not stop fighting until they "pray in Rome", in another hint they could be plotting to take out the Pope.
William McCants, a US expert on jihadism, said: "The Muslim armies are supposed to take over Rome, and eventually they are supposed to take over the whole world.
"The group believes that Muslims will conquer the Italian capital in the course of conquering the entire world. There will be an ultimate victory for Islam and then the end of the world comes."