It's easy to "lawyer up"(twist words to persuade) when it comes to the word "belief", or almost ANY word. That being said....YES. Atheists have beliefs, whether they admit it or not, and so do Agnostics. The belief is that they don't think God exists, or is real..or the Creator of everything. Their belief is that the Bible is flawed; contradictory; Jewish fairy tales. But that's STILL belief.
What is belief? Your Personal Truths you live by. Whether you can prove it's true or not, that's what you believe, live by, and call "truth". This applies to what IS true, and what is lies/self-deception.