  We study the non-equilibrium work in a pedagogical model of relativistic
ideal gas. We obtain the exact work distribution and verify the Jarzynski's
equality. In the non-relativistic limit, our results recover the
non-relativistic results [arXiv:cond-mat/0502434]. We also find that, unlike
the non-relativistic case, the work distribution no longer has zeros and the
number of collisions in this relativistic gas model is finite. In addition,
based on an analysis of the experimental parameters, we conclude that it is
difficult to detect the relativistic effects of the work distribution of the
ideal gas in a piston system with the current experimental techniques.
