Device (1) for filtering electromagnetic interference, comprising:—a plurality of electrical conductors (5) mounted in parallel, each conductor (5) comprising a first coil (10) disposed between a first (7) and a second (8) end of the conductor (5), said first coils (10) being coupled magnetically together and exhibiting one and the same first number of turns, said first (7) and second (8) ends of the conductors (5) respectively defining first (7) and second (8) terminals for the device,—a plurality of capacitors (13), each capacitor (13) being mounted between the second end (8) of an electrical conductor (5) and a third terminal (15) of the device, and—an additional circuit (20) comprising a second coil (21) coupled magnetically with the first coils (10) and exhibiting a second number of turns, said circuit (20) furthermore comprising an additional coil (23).