Abstract This work is the first in what appears to be a comprehensive treatise on ultraclean technology in the semiconductor industry and other industries that require ultraclean technology. As the title indicates, this is a handbook, or more accurately, an in-depth encyclopedic treatment of the subject. Its audience includes scientists, engineers, and others involved with virtually any aspect of ultrapure water, and, although the author's target is the semiconductor industry, this volume is valuable to anyone working with ultrapure water.