Authors: Mike W Davis, Tadeusz Januszkiewicz and Ian J Leary Mike Davis Affiliation: The Ohio State University Tadeusz Januszkiewicz Affiliation: The Ohio State University Ian Leary Affiliation: The Ohio State University Abstract: We compute the $\ell^2$-Betti numbers of the complement of a finite collection of hyperplanes in the complex space $\Bbb C^n$. At most one of the $\ell^2$-Betti numbers is non-zero. If the arrangement of hyperplanes is essential (i.e., not the product of $\Bbb C$ with a lower-dimensional arrangement) then the $n$th $\ell^2$-Betti number is the one that can be non-zero. Status: preprint