  Cosmlogical domain walls produced during phase transition are expected to
collapse on a cosmologically safe timescale if Vilenkin's condition is
satisfied. We show that the decaying processes of these unstable domain walls
should be changed significantly if weak scale inflation takes place. The usual
condition for the safe decay of the cosmological domain wall must be changed,
depending on their scales and interactions. As a result, the energy scales and
explicit breaking terms of such walls must satisfy severe requirements. We also
make a brief comment on cosmological structure formation.
