  Photon-photon scattering at the Photon Linear Collider is considered.
Explicit formulas for helicity amplitudes due to $W$ boson loops are presented.
It is shown that photon-photon scattering should be easily observable at PLC
and separation of the $W$ loop contribution (which dominates at high energies)
will be possible at $e^+e^-$ c.m. energy of 500~GeV or higher.
