  After a brief review of the Maxwell-like approach to gravity we consider the
issue of the negative energy of gravitational field which is a consequence of
the field approach to the phenomenon of gravitation. Due to the existence of
the negative field energy {\it within} a mass body its total energy content is
smaller than the positive energy assigned to its mass energy. We study the
total energy content of a spherically symmetrical mass body having constant
matter density, and show that its total energy content depends on its radius.
We show that under certain circumstances, the total energy content of a mass
body achieves negative values so that the force at its surface becomes
repulsive. We apply this idea to the evolution of universe filled by matter and
the negative energy density of its gravitational field. Since the negative
energy density causes the negative pressure it might be considered as an agent
which causes the acceleration of the universe.
