The possibility of controlling the magnetic properties of multilayered periodical structures with perpendicular magnetic anisotropy, which are based on cobalt and platinum films, have been studied. The multilayered films composed by layers with a thickness of 0.5–1.0 nm were subjected to two types of actions: vacuum annealing at different temperatures and irradiation by helium ion beams. Transmission electron microscopy has shown that the irradiation by He⁺ ions with energy of 30 keV leads to material mixing in the layers since at vacuum annealing the layered structure of films is kept. In this case, as a result of thermal annealing, the coercive force of the structure increases significantly, and upon irradiation with helium ions, the coercivity of the films decreases to a change in the type of anisotropy from perpendicular to “easy plane” anisotropy.