This paper deals with a Hausdorff moment problem with complex exponents, that is, given a sequence of complex numbers (zn), and a fixed space X of functions defined on [O, 11, we ask under which conditions on a sequence ( u~)~ the moment problem a, = & l t " -f ( t ) dt for n E N has a solution in the space X. Mainly, we study the solution belonging to the space 'D[o,JI. The results which we will obtain will lead us to prove a Miinta-Szass Theorem for distributions.First, we study and solve when the Hausdorff moment problem always has a solution, that is, we characterize in a simple way the complex sequences (z,), satisfying that for every complex sequence (a,), there exists a function f such that the functions t z n f ( t ) are Lebesgue integrable in [0,1] and a, = 1 ; tznf(t) dt. In fact, a necessary and sufficient condition on (z,), is the following: If we put p = inf {%z, : n 2 0}, then limn %z, = p, %z, # p for all n 2 0, and z, # zm if n # m. This result completes