I found it!!

Reply to post of user Mikhail Luzyanin
Yes, it's really easy, so, I can't understand what you are doing wrong. I've attached an example for you and marked a parameters that have matter for transparency setup.

transparancy.blend

Hi, I can't find the Transparency options showed in your print screem, I'm using Blender version 2.79. Can you help me?

Thanks.