An apparatus for measuring electrical currents in an electrical circuit, said apparatus comprising a plurality of current sensors (61, 62, 63) of the Rogowski type, each adapted to measure an electrical current flowing in an electrical conductor (31, 32, 33), said current sensors being adjacent to each other and each comprising: - coils (64, 64') capable of being electrically connected to each other to form a current measuring circuit, - a central opening (61C, 62C, 63C) for receiving the corresponding electrical conductor (31, 32, 33), the coils (64, 64') being arranged around the central opening, the measuring apparatus comprising a plurality of ferromagnetic rods, each current sensor (61, 62, 63) comprising two of said coils (64, 64'), arranged parallel and facing each other on opposite edges of the central opening (61C, 62C, 63C) and two of said ferromagnetic rods, extending between ends of the coils (64, 64'), perpendicular to a longitudinal axis (X64, X64') of the coils, each current sensor (61, 62, 63) having a ferromagnetic rod in common with the immediately adjacent current sensor, characterised in that the apparatus comprises first and second armatures (66, 66') arranged parallel to each other and common to all current sensors (61,62, 63) of the apparatus, each of the first and second armatures (66, 66') having a rectilinear portion, the coils (64, 64') of each current sensor being respectively provided on these first and second armatures by winding around this rectilinear portion, and in that each of the first and second armatures (66, 66') comprises housings (661, 662, 663) each adapted to receive one end of one of the ferromagnetic bars. - coils (64, 64') capable of being electrically connected to each other to form a current measuring circuit, - a central opening (61C, 62C, 63C) for receiving the corresponding electrical conductor (31, 32, 33), the coils (64, 64') being arranged around the central opening, the measuring apparatus comprising a plurality of ferromagnetic rods, each current sensor (61, 62, 63) comprising two of said coils (64, 64'), arranged parallel and facing each other on opposite edges of the central opening (61C, 62C, 63C) and two of said ferromagnetic rods, extending between ends of the coils (64, 64'), perpendicular to a longitudinal axis (X64, X64') of the coils, each current sensor (61, 62, 63) having a ferromagnetic rod in common with the immediately adjacent current sensor, characterised in that the apparatus comprises first and second armatures (66, 66') arranged parallel to each other and common to all current sensors (61,62, 63) of the apparatus, each of the first and second armatures (66, 66') having a rectilinear portion, the coils (64, 64') of each current sensor being respectively provided on these first and second armatures by winding around this rectilinear portion, and in that each of the first and second armatures (66, 66') comprises housings (661, 662, 663) each adapted to receive one end of one of the ferromagnetic bars. each current sensor (61, 62, 63) comprising two of said coils (64, 64'), arranged parallel and facing each other on opposite edges of the central opening (61C, 62C, 63C) and two of said ferromagnetic rods, extending between ends of the coils (64, 64'), perpendicular to a longitudinal axis (X64, X64') of the coils, each current sensor (61, 62, 63) having a ferromagnetic rod in common with the immediately adjacent current sensor, characterised in that the apparatus comprises first and second armatures (66, 66') arranged parallel to each other and common to all current sensors (61,62, 63) of the apparatus, each of the first and second armatures (66, 66') having a rectilinear portion, the coils (64, 64') of each current sensor being respectively provided on these first and second armatures by winding around this rectilinear portion, and in that each of the first and second armatures (66, 66') comprises housings (661, 662, 663) each adapted to receive one end of one of the ferromagnetic bars.