  In this work is presented the microcanonical analysis of the blackbody
radiation. In our model the electromagnetic radiation is confined in an
isolated container with volume V in which the radiation can not escape,
conserving this way its total energy, E. Our goal is to precise the meaning of
the Thermodynamic Limit for this system as well as the description of the
nonextensive effects of the generalized Planck formula for the spectral density
of energy. Our analysis shows the sterility of the intents of finding
nonnextensive effects in normal conditions: the traditional description of the
blackbody radiation is extraordinarily exact. The nonextensive effects only
appear in the low temperature region, however, they are extremely difficult to
detect.
