  We propose a new iterative method to directly calculate the spontaneous mass
generation. It is regarded as a new regularization method resembling the finite
volume calculation which assures non-negative fluctuation property at every
stage. We work with the Nambu--Jona-Lasinio model and the strong coupling gauge
theory where the dynamical chiral symmetry breaking occurs. We are able to
conclude the physical mass definitely without encountering any singularity nor
recourse to any additional consideration like the free energy comparison.
However in special case of the 1st order phase transition, we find that the
iterative method has a chance to go wrong.
