  The distribution function of local amplitudes of eigenstates of a
two-dimensional disordered metal is calculated. Although the distribution of
comparatively small amplitudes is governed by laws similar to those known from
the random matrix theory, its decay at larger amplitudes is non-universal and
much slower. This leads to the multifractal behavior of inverse participation
numbers at any disorder. From the formal point of view, the multifractality
originates from non-trivial saddle-point solutions of supersymmetric
$\sigma$-model used in calculations.
