As far as historians know, and depending on what one means by "made," the first book was either the Epic of Gilgamesh, the first bound copies of the Bible, or the Gutenberg Bible. Each marks a point in the development of books.
The Epic of Gilgamesh is the oldest-known written story that can be called a book. It was written in ancient Sumeria sometime prior to the 18th century B.C. on clay tablets. The first bound parchment books, or codices, were the Bibles of the early Christian church, like the 4th century A.D. Codex Vaticanus and the Codex Sinaiticus. Much later, in 1454 or 1455, Johann Gutenberg printed the first book on a moveable-type printing press: the Gutenberg Bible.