It kinda is. There is a single chapter devoted entirely to religion, but it also has a chapter called the junkyard jumbo jet, or something like that. He argues that people believe in intelligent design because if a whirlwind blows through a junk yard, it aint going to build a jumbo jet out of the parts. Therefore there has to be a creator.
It's an argument against there being a god, as the entire book is, or at least the idea that if there is a god, he isn't required.
Did he also write the blind watchmaker, it's much more complex than the god delusion, but not aure if dawkins wrote it