It's a pencil drawing.

Diego Fazio aka DiegoKoi is an Italian artist from the town of Lamezia. Born in 1989, the self-taught illustrator first started as a tattoo artist and says he was initially inspired by the artwork of Katsushika Hokusai, a highly influential Japanese artist from the Edo period.

Now twenty-five, Diego only began drawing in 2007, yet his hyperrealistic pencil drawings on paper and wood have gained him international acclaim. Each portrait can take up to two hundred hours but the results speak for themselves.

You can follow his progress at these links:
DiegoKoi ART  deviantART | Facebook