  We discuss in detail the possibility of determining dynamicaly the gravitino
mass $m_{3/2}$, which is related to the supersymmetry breaking scale, within
the minimal supersymmetric standard model (MSSM). Using the complete MSSM
spectrum, we minimize the vacuum energy including one-loop corrections and a
cosmological term of ${\cal O}(m_{3/2}^4)$ induced by the underlying
fundamental theory. We find that both terms are necessary to determine
dynamically the gravitino mass. Other useful constraints for the low energy
phenomenology are also obtained.
