I'm new in Camping, and recently I have camped in France, in the Vosges region, in the locality called "Le bonhomme".
Well it's not the pure wilderness but it was very unusual for me, as it was nobody around and I was in a dense forest.
I know there was wild boars, grey wolves (and maybe boreal lynx)
So, how to keep away those animals from my camp without setting a fire?
I haven't seen any evidence that animals are kept away by a fire. This answer discusses that briefly. In general, wild animals in pristine backcountry areas tend to be wary of humans, simply because we're unfamiliar. Some animals, such as squirrels and bears, that live in heavily used areas can become dependent on human food, and they will then become habituated to humans. In areas like Yosemite Valley, these are animals that cruise the campgrounds nightly. They're certainly not staying away from campgrounds because there are fires.
Wolf attacks are extremely rare in Europe. A study of wolf attacks states: "Since wolves recolonised France in the late 1980's after almost a century of absence there have been no documented attacks on humans." If you get an opportunity to see a wolf in the wild, you could celebrate it as a rare, once-in-a-lifetime experience to see an animal that has been driven almost to extinction. In times and places where wolf populations are less endangered, it appears that many attacks are by rabid wolves. I doubt that there is much you can do to deter a rabid animal. Note that many different animal species carry rabies, e.g., skunks and bats.
Your most likely problems when dealing with wild animals are hassles, not attacks, and those hassles are likely to revolve around small animals and their attempts to get your food. To avoid those hassles, the most straightforward thing you can do is to take measures to prevent animals from getting access to your food, and to hide the smell of your food. For example, you can keep all your food sealed inside zip-lock bags, and you can hang your food from a tree or put it inside a hard-sided canister or a kevlar sack such as the ursack.
While @Ben has written a pretty nice answer, I'll tackle the OP's question a little more directly with a couple of concrete suggestions:
Note, however, that these methods may not be entirely effective, depending exactly on what sort of animal you are dealing with.
Related to flith's answer, noise can be a deterrent. The same way fires are prohibited in some areas, making too much noise may also be frowned upon, so this may not be a viable strategy depending on where you are.
Wilderness survival expert Les Stroud carries a harmonica as a personnel item and to provide some comfort. He has noted a thought, as I and others have as well, that the harmonica noise can deter animals (while also providing personal comfort before bed).
The saying 'they are more scared of you than you are of them' applies here - animals need to exercise caution as a matter of survival, and approaching a strange creature is risky. Approaching a strange creature that appears very large, fierce, fearless, or making disturbing, loud, piercing sounds (like those from a harmonica) may also appear risky and cause more animals to avoid the area accordingly.
