Current transformer comprising: - a first coil and a second coil, said coils being formed by means of a first printed circuit board of substantially parallelepipedal shape, said printed circuit board comprising a first upper face, a first lower face, a first side, a second side, the second side being opposite to the first side, a third side and a fourth side, the fourth side being opposite to the third side, the first coil being formed from first turns (11, 13, 14) coiled about a first coiling axis that is substantially perpendicular to the third and fourth sides (55, 56), the second coil being formed from second turns (21, 23, 24) coiled about a second coiling axis that is substantially perpendicular to the third and fourth sides (55, 56), the first printed circuit board comprising a first aperture in the first upper and lower faces (51, 52) so as to form a through-passage for a current line, said current line forming a primary circuit of the current transformer, the first coil and the second coil (10, 20) being placed on either side of the first aperture and forming a secondary circuit, and - a first magnetic part of elongate shape comprising a first reference face and at least one second magnetic part of elongate shape comprising a second reference face, the current transformer being characterized in that: - the first printed circuit board comprising a first positioning means, placed in proximity to the third side, and a second positioning means placed in proximity to the fourth side, - the first magnetic part comprising a first maintaining means, - the second magnetic part comprising a second maintaining means, the first positioning means is arranged to be assembled with the first maintaining means to keep the first reference face at a preset distance facing the third side, and the second positioning means is arranged to be assembled with the second maintaining means to keep the second reference face at a preset distance facing the fifth side. - a first coil and a second coil, said coils being formed by means of a first printed circuit board of substantially parallelepipedal shape, said printed circuit board comprising a first upper face, a first lower face, a first side, a second side, the second side being opposite to the first side, a third side and a fourth side, the fourth side being opposite to the third side, the first coil being formed from first turns (11, 13, 14) coiled about a first coiling axis that is substantially perpendicular to the third and fourth sides (55, 56), the second coil being formed from second turns (21, 23, 24) coiled about a second coiling axis that is substantially perpendicular to the third and fourth sides (55, 56), the first printed circuit board comprising a first aperture in the first upper and lower faces (51, 52) so as to form a through-passage for a current line, said current line forming a primary circuit of the current transformer, the first coil and the second coil (10, 20) being placed on either side of the first aperture and forming a secondary circuit, and - a first magnetic part of elongate shape comprising a first reference face and at least one second magnetic part of elongate shape comprising a second reference face, - the first printed circuit board comprising a first positioning means, placed in proximity to the third side, and a second positioning means placed in proximity to the fourth side, - the first magnetic part comprising a first maintaining means, - the second magnetic part comprising a second maintaining means,