I don't believe there are gods. Like others have said, it's a lack of a belief. No faith required.
I purposefully say "gods" because there are many gods i don't believe in. Thor, baal, osiris, jaweh, etc etc. I'm a polyatheist!
Of course i can't say for absolute certain that there are no gods, just as i can't say for absolute certain that there are no leprechauns, flying spaghetti monsters, or teapots orbiting the sun.
But not all probabilities are equal. Just because you cannot disprove something, it doesn't mean it's equally likely to exist as to not exist.
I assume people who are agnostic on this principle are equally agnostic about fairies, pink unicorns, etc?
I don't believe in gods in the exact same way that i don't believe in those.
I don't feel the need to describe myself as agnostic, because as far as i'm concerned, the possibility of any of those things existing is so mind bogglingly tiny, that i'm convinced they don't exist.
It's that simple for me.