  We study the orbital magnetism of 2D lattices with chaotic motion of
electrons withing a primitive cell. Using the temperature diagrammatic
technique we evaluate the averaged value and rms fluctuation of magnetic
response in the diffusive regime withing the model of non-interacting
electrons. The fluctuations of magnetic susceptibility turn out to be large and
at low temperature can be of the order of $\chi_{L} (k_{F}l)^{3/2}$, where
$k_{F}$ is the Fermi wavevector, $l$ is the mean free path, and $\chi_{L}$ is
the Landau susceptibility. In the certain region of magnetic fields the
paramagnetic contribution to the averaged response is field independent and
larger than the absolute value of Landau response.
