  We investigate the pressure of the pion, which should be equal to zero to
ensure the stability of the pion, within the framework of the chiral quark
model beyond the chiral limit. The pressure of the pion turns out to vanish
nontrivially by the Gell-Mann-Oakes-Renner relation within the present
framework. It implies that the stability of the pion might be deeply rooted in
spontaneous chiral symmetry breaking. We also discuss physical quantities
relevant to the energy-momentum tensor operator.
