  We construct a model consisting of many D3-branes with only positive tension
in a five-dimensional anti-de Sitter space-time geometry. It is shown that this
type of model naturally realizes not only exponential mass hierarchy between
the Planck scale and the electroweak scale but also trapping of the graviton on
the D3-branes. It is pointed out that our model may have a flexibility to
explain the existence of more than one disparate mass scales, such as the
electroweak scale and the GUT scale, on the same D3-brane.
