Is atheism a belief?

[Angrboda]

Note that it's also possible to be agnostic about the question of whether you know that no gods exist or not, because whether you know that no gods exist is another thing you may or may not believe. I find myself in that category because what it means to know something is not itself known with any certainty. Depending on the constraints and demands you place on knowledge, the proposition that no gods exist is known may or may not be true. There's also the question of whether the concept of a god is sufficiently narrowly defined to have a determinative answer on the question. As noted by other posters, some will claim to know that specific, well-defined gods do not exist, but be more agnostic on others. I tend to believe the concept of a god is sufficiently narrowly and clearly defined that such a step is not necessary, but I recognize that opinions on that differ, and like the question of knowledge, it touches on some deep issues which are far from settled.

As to your specific question, atheism can consist of a belief, but it isn't necessary that it do so. In the event that it does, the only belief involved is that whether gods or a god exists is knowable and known. Typically when people refer to atheism being a belief, they are interested in the idea that atheists believe other things, like metaphysical naturalism, rather than this one modest belief. The latter is not atheism, as defined by most atheists.