  The Affleck-Dine mechanism creates the baryon asymmetry of the universe from
an angular motion of a complex scalar field. The mechanism is efficient and
allows for a low reheating temperature of the universe if the scalar field has
a flat potential along its radial direction. We consider a possibility where
the scalar field is a pseudo-Nambu-Goldstone boson arising from spontaneous
breaking of an approximate global symmetry, so that the flatness of the
potential is naturally understood. We construct a concrete realization of the
idea based on chiral symmetry breaking in an SU(N) gauge theory. The
Peccei-Quinn mechanism can be consistently incorporated into the model. We also
comment on a possible impact of the model on early universe physics.
