  We discuss a new model of quintessence in which the quintessence field is
identified with the extra-component of a gauge field in a compactified
five-dimensional theory. We show that the extremely tiny energy scale $\sim
(3\times 10^{-3} eV)^4$ needed to account for the present acceleration of the
Universe can be naturally explained in terms of high energy scales such as the
scale of Grand Unification.
