How to aproach when thesis supervisor just "disappear"? My thesis supervisor is not reviewing my thesis. I wanted to discuss for my three years degree the development of my 3D engine (Computer science thesis). I mailed to the professor about my intention, he wanted to see me for a brief meeting (June) where I explained him what's different in my work and a short roadmap of work that had to be done and what I was already developing.

I completed my thesis PDF in last days of August. I mailed about that to the professor and he replied he was busy so I had to skip the graduation session of October, he just asked to hold on. Then I mailed him again, I got no reply until it was too late for session of December.

In last email he just took a quick look at my thesis saying stuff "it is not a typical thesis, however for a 3 years degree it should do even if it has ingenuities I will contact you before Christmas, I should have enough time to follow you until Genuary the 10th, however I remember you it was your initiative".

Shouldn't be a thesis anyway my initiative?

However now we are After Christmas and still got no reply. What I should do? it has been almost 6 months without having been followed. I do not want to skip also the March session. What should think someone hiring me? I completed all exams in time and with good rating. 

Now Employeers will just see someone "graduated in 4 years instead of 3" just because a teacher did not review my thesis when I did a enourmous amount of work in research, study and development.

Why simply the professor didn't told me "I have no time to follow you, search someone else"?
I had one of those issues when I was doing a PH.D.  You should contact your supervisor first and cc the department head. That way you have more people in the loop. In that email, make an appointment.  If the supervisor doesn't get back to you, that's a red flag. You will be able to then speak to the department head about it and he/she will have some context when you see him/her. In that meeting with the head, speak about your issue. They will solve the problem. 

If your supervisor does get back to you, which I assume he/she will since the department head is now in the loop, don't be confrontational. Just have a normal discussion about how you couldn't get a response and that you need more help. 

That's how I'd approach it.