  Magnetic fields in galaxy clusters can be investigated using a variety of
techniques. Recent studies including radio halos, Inverse Compton hard X-ray
emissions and Faraday rotation measure, are briefly outlined. A numerical
approach for investigating cluster magnetic fields strength and structure is
presented. It consists of producing simulated rotation measure, radio halo
images, and radio halo polarization, obtained from 3-dimensional multi-scale
cluster magnetic field models, and comparing with observations.
