A magnetically-tunable filter comprising a filter housing with two tunable resonator spheres made of magnetizable material, which are disposed one above the other in two filter arms. At least one filter arm provides a fin line or slot line disposed on a substrate layer and extending in the direction towards an electrical contact, and a common coupling aperture, thereby connecting the two filter arms to one another. In this context, one resonator sphere is positioned within each filter arm on each of the two sides of the coupling aperture.