  As an analogue of Mahler's classification for real numbers, Bundschuh
introduced a classification for Laurent series over a finite field, divided
into $A,S,T,U$-numbers.It is known that each of $A,S,U$-numbers is nonempty.On
the other hand, the existence of $T$-numbers is open.In this paper, we give an
affirmative answer to the problem.
