It is some kind of scale insect. I would start by dabbing each of those bumps with methyl alcohol. That might take several days of intermittent attention, to get them all. Also, spray the whole plant with a solution of organic dish soap, to get all of the minute, crawling juveniles. Best of luck!

Thank you. But I just wonder if "white dots" and " demage leaves" aren't two diferent diseases.

You need to find out what's causing the white scale. They are parasites and will eventually kill your tree. Lack of air movement is a major cause. Olive trees like open air with lots of wind and sun.

If its in the room with other plants, I suggest that you remove it and keep it in isolation or discard it.

If your tree came from Italy, I would burn it. Italy has a problem with Xylella fastidiosa, which is destroying their olive trees. Anyone who imports a plant from Italy is risking the spread of Xf - the list of vector plants is very long and has caused most plants to be banned from importation to the EU since May 2015.

This looks a lot more like mealy bug though so don't panic until you have tried the methyl alcohol. If the white spots disappear immediately its a scale insect (mealy bug is one of them that looks white like yours)
If this works have a look at the roots too as they can also be affected. You will need to wash off all the compost and treat the roots individually with the methyl alcohol.Treat the inside of the pot as well. Repot in clean compost.

The symptoms showing do not resemble Xyella fastidiosa infection, and it would appear to be a scale or mealybug infestation. Methylated spirits is usually the commonest source of methyl alcohol, and you can use that in the same way as suggested in the first answer above.

I agree it is mealybug, but the leaf problem could be a virus or environmental stress. It would be far happier outside - even on a balcony. If that isn't possible for you - why not give it to a friend with a garden (when the mealybug are dead!) and get yourself a houseplant that will enjoy being in a house.

Definitely a scale, not a mealybug. The distorted leaves look like the sort of damage that scale does when it attaches itself to leaves that are still young and expanding, Inienka. Controlling the scale should stop the production of distorted leaves, though those already affected won't straighten out. It is hard to tell from here what other plants the scale might attack, but I have seen similar scale on Ficus, Hoya, and cacti.

Thank you everyone.I think it isn't mealybug or Xyella fastidiosa. It will be some sort of scale insect. I have never seen this concrete scale insect therefore I was really confused about distorted leaves. So thank Tugbrethil for explain me. I will try to wipe it off.
Unfortunately your good ideas about making better enviromental for tree, it is not possible. (I have been thinking about the same for some time.) Because tree is not mine, I am just gardener who take care of it. Tree was planted in the ground (6 years ago) in glazed atrium in casino. Air condition is misty (from smoking) and very hot for all year.

Good light then, at least. Outdoors, scale insects are less common and destructive than on plants indoors, mainly beause their natural predators don't fly in the door as often as they do! Treating the soil with a dilute mixture of saponin and fulvates will help the tree to deal with the smoking residues, though getting those products in Europe may be problematical, from what I hear. Possibly more available sources are aloe juice and home made compost tea. That treatment should also help it to resist similar infestations of insects--such as mealybugs! :)

The spirit should deal with most sorts of scale insect.