Kant refuted Anselm's ontological proof of God's existence by claiming that "being" is not a predicative word but only a link verb. Yet Alvin Plangtinga wants to say that "being" is a predicative word, though a special one. Unlike other predicative word, this one cannot predicate by itself but always has to have another predicate going along with itself. This article would like to argue that even if "being" is a predicative word, just because it is that kind of "special" predicative word as Plantinga has pointed out, Anselm's ontological proof of God's existence cannot stand. Further, an attempting effort is made to provide a proof that this kind of "proof of God's existence" is impossible. Its ultimate mistake lies in its treating God in line with other objects that exist in this world.