  In order to compare recent experimental results with theoretical predictions
we study the influence of finite conductivity of metals on the Casimir effect.
The correction to the Casimir force and energy due to imperfect reflection and
finite temperature are evaluated for plane metallic plates where the dielectric
functions of the metals are modeled by a plasma model. The results are compared
with the common approximation where conductivity and thermal corrections are
evaluated separately and simply multiplied.
