No, Atheism is a claim to the nature of reality and the universe but is not generally a prescribed belief (in the sense that the only universal claim is that any or all God's and concepts of God are false). It still is a belief (whether an atheist would admit it or not) that assumes in itself a self-validation in the assessment of the nature of the universe in a self-perceived "rational" lens, often favoring materialism. (on the extreme but not uncommon side of the spectrum, is those who treat Science religiously, as an unquestionable infallible authority)
If one simply doesn't believe in a God but makes no claim about the existence or non-existence of "God", then they would be an agnostic.
All reality-tunnels are flawed though, regardless of whether there is a belief in God involved or not.