A magnetic field applicator for the magnetic stimulation of body tissues comprising a core carrier (1) in which a plurality of magnetically conductive flow guide pieces comprised of layered iron sheets is disposed, upon which at least one live coil (3) is disposed that generates an upward-emitted magnetic field having a plurality of field line bundles (8), wherein the magnetic field applicator comprises a polygonal coil (3) that is wound as a pancake coil in one or more planes in such a way that the direction of the individual coil conductors (27) is selected such that the coil conductors (27) run in pieces in a predominantly straight line and perpendicular to the plane of the flow guide pieces that are made of layered sector iron cores (5-8).