The results of experimental studies using optical profilometry and scanning probe microscopy of the structure and surface parameters of germanium single crystals exposed to an alternating magnetic field are presented. The change in parameters of surface roughness and relief of single crystals after treatment by magnetic field was found. Using optical spectroscopy, a decrease in transmittance in the range of 1.8—23 μm was established, due to the influence of an alternating magnetic field, leading to a change in the surface topography.