A multi-phase stray field transformer used for storing energy and filtering currents with a number of 2*n+1 phases, wherein “n” represents a natural number, comprising a core (11, 12, 13, 14) with 2*n+1 of first yokes (11, 11a) with one winding (2) arranged on every first yoke and with at least one additional (second) yoke (12) that is connected to the rest of the core (13, 14) across an air gap (3) and/or exhibits such an air gap (3) with the core (11, 12, 13, 14) of the transformer being provided with 2*n second yokes (12) that are arranged with the first yokes (11) in an alternating fashion.