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 coiled about a first coiling axis (X1) that is substantially perpendicular to the third and fourth sides , the second coil being formed from second turns coiled about a second coiling axis (X2) that is substantially perpendicular to the third and fourth sides , the first printed circuit board comprising a first aperture in the first upper and lower faces 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 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 coiled about a first coiling axis (X1) that is substantially perpendicular to the third and fourth sides , the second coil being formed from second turns coiled about a second coiling axis (X2) that is substantially perpendicular to the third and fourth sides , the first printed circuit board comprising a first aperture in the first upper and lower faces 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 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 , <EOS>