  We consider the Casimir effect of a massive vector field between two
semi-infinite dielectric slabs. We first derive the generalization of the
Lifshitz formula that gives the Casimir interaction energy of two
magnetodielectric slabs separated by a magnetodielectric medium due to the
vacuum fluctuations of a massive vector field. We then discuss the asymptotic
behaviors of the Casimir energy and the Casimir force in various limits, such
as low temperature, high temperature, small mass, large mass, up to the first
order in the finite conductivity correction, for two real metal semispaces
whose dielectric property is described by the plasma model. Application to the
Casimir effect in Randall-Sundrum spacetime is briefly discussed.
