Atheism isn't a belief any more than fasting is a meal or a bare chest is a shirt. This argument rests on the misconception (bordering on a straw man) that atheism is the positive belief that there are no gods. That's not what atheism is. Atheism is simply the lack of belief in any gods. There is a difference between "I do not believe that God exists" (atheism) and "I do believe that God does not exist" (so-called "positive atheism").
Some atheists are positive atheists, but for most of us it's at best a suspicion or a working hypothesis, not a matter of absolute, infallible, unquestioned belief.
Even if we are to consider the belief that there are no gods, I would still question whether or not this belief depends on faith any more than the various beliefs that there are gods. If you study the history of philosophy you'll find a number of supposed "proofs" of the existence of God. There are also many arguments for the non-existence of God. It's a matter of argument and cautioned reasoning, not faith, whether or not to believe that God exists.
Faith is an epistemic position that the atheist does not share. Most atheists tend to acquire beliefs based upon evidence. Just like everyone else, an atheist goes home at night expecting that his house is where he left it that morning. But, just like everyone else, an atheist would be surprised to find that his house had burned down. Yet, after some amount of emotional torment, the atheist would be forced to believe that his house was, in fact, no longer standing.
Contrast this with religious belief. A positive atheist, upon coming across some unquestionable evidence of God's existence, would be surprised but would be forced to accept what the evidence has shown. Someone of religious faith would come across unquestionable evidence that God did not exist and refuse to believe it. They would in fact rearrange their entire belief system simply to preserve their non-rational, privileged belief that God exists and will save them from eternal damnation in exchange for their faith.
Keep in mind, that is the ideal case. People of faith can be better empiricists than the demands of faith allow them to be, just as empiricists can be more dogmatic than the demands of empiricism allow them to be. But while most atheists consciously choose empiricism (and reject belief in God because there is no good evidence for it), people of faith consciously choose faith. This is the real difference. It's not about God, it's about how people choose to form their beliefs.
(OK--let's be more clear here. An atheist can still have faith in something else. For instance, most Buddhists are atheist because of their faith in the possibility of mystical enlightenment and so forth. The real difference isn't between religious people and atheists, but between religious people and secularists. Just as atheists can be religious, secularists can believe in God. Such secularists are known as "deists" and many of them did remarkable things, such as writing the Declaration of Independence.)