  A structure of the radiation-ball which is identified as a Schwarzschild
black hole is found out by investigating the backreaction of Hawking radiation
into space-time. The structure consists of the radiation which is
gravitationally bounded in the ball and of a singularity. The entropy of the
radiation in the ball is proportional to the surface-area of the ball and
nearly equals to the Bekenstein entropy. The Hawking radiation is regarded as a
leak-out from the ball. There arises no information paradox because there
exists no horizon in the structure.
