  The basic results in calculations of the thermodynamic functions of
electromagnetic field in the background of a dilute dielectric ball at zero and
finite temperature are presented. Summation over the angular momentum values is
accomplished in a closed form by making use of the addition theorem for the
relevant Bessel functions. The behavior of the thermodynamic characteristics in
the low and high temperature limits is investigated. The $T^3$-term in the low
temperature expansion of the free energy is recovered (this term has been lost
in our previous calculations).
