  We propose a scenario where superheavy dark matter (DM) can be produced via
symmetry restoration first-order phase transition during inflation triggered by
the evolution of the inflaton field. The phase transition happens in a
spectator sector coupled to the inflaton field. During the phase transition,
the spectator field tunnels from a symmetry-broken vacuum to a
symmetry-restored vacuum. The massive particles produced after bubble
collisions are protected against decaying by the restored symmetry and may
serve as a DM candidate in the later evolution of the Universe. We show that
the latent heat released during the phase transition can be sufficient to
produce the DM relic abundance observed today. In addition, accompanied with
the super heavy DM, this first-order phase transition also produces
gravitational waves detectable via future gravitational wave detectors.
