  The electrostatics properties of composite materials with fractal geometry
are studied in the framework of fractional calculus. An electric field in a
composite dielectric with a fractal charge distribution is obtained in the
spherical symmetry case. The method is based on the splitting of a composite
volume into a fractal volume $V_d\sim r^d$ with the fractal dimension $d$ and a
complementary host volume $V_h=V_3-V_d$. Integrations over these fractal
volumes correspond to the convolution integrals that eventually lead to the
employment of the fractional integro-differentiation.
