  The dynamics at the IR fixed point realized in the $SU(N_c)$ gauge theories
with massless Dirac fermions is studied by means of the non-perturbative
renormalization group. The analysis includes the IR fixed points with
non-trivial Yukawa couplings. The renormalization properties of the scalar
field are also discussed and it is shown that hierarchical mass scale may be
allowed without intense fine-tuning due to a large anomalous dimension.
