A sensor for measuring a current (i) in an electrical cable, the sensor comprising an electrical circuit and a support for the electrical circuit, the electrical circuit being designed to surround the electrical cable during said measurement, forming a loop, the support having an opening interrupting the loop and the support comprising two ends (14, 16) located on either side of the opening, the electrical circuit comprising a helical winding, the sensor further comprising a handle fixed to the support to press the opening of the support against the electric cable, the support being elastically deformable between: - a first position in which it is at rest and the two ends (14, 16) are substantially opposite each other, and - a second position in which the two ends (14, 16) are spaced apart from each other relative to the first position, the support being sufficiently flexible and being shaped so that: - the support can be deformed from the first position to the second position by manually pressing the opening of the support against the electrical cable, so as to cause the electrical cable to pass from the outside of the loop to the inside of the loop, or from the inside of the loop to the outside of the loop, and - the support returns spontaneously from the second position to the first position, once the electrical cable has passed through the opening, the support comprising a first external guide and a second external guide for channelling the electrical cable to the opening of the holder and facilitating the deformation of the support from the first position to the second position, when the electrical cable and the opening of the support are pressed towards each other, the electrical cable being located outside the loop, the handle comprising a substantially straight main part intended to be held by an operator, the handle further comprising an end part integral with the support and forming an obtuse angle with the main part, the end part forming the second external guide, the sensor being characterised in that it comprises a position-holding element for the electrical cable, the position-holding element being located inside the loop formed by the support and comprising a housing for receiving the electrical cable in a predefined position relative to the electrical circuit. - a first position in which it is at rest and the two ends (14, 16) are substantially opposite each other, and - a second position in which the two ends (14, 16) are spaced apart from each other relative to the first position, the support being sufficiently flexible and being shaped so that: - the support can be deformed from the first position to the second position by manually pressing the opening of the support against the electrical cable, so as to cause the electrical cable to pass from the outside of the loop to the inside of the loop, or from the inside of the loop to the outside of the loop, and - the support returns spontaneously from the second position to the first position, once the electrical cable has passed through the opening, - the support can be deformed from the first position to the second position by manually pressing the opening of the support against the electrical cable, so as to cause the electrical cable to pass from the outside of the loop to the inside of the loop, or from the inside of the loop to the outside of the loop, and - the support returns spontaneously from the second position to the first position, once the electrical cable has passed through the opening, the support comprising a first external guide and a second external guide for channelling the electrical cable to the opening of the holder and facilitating the deformation of the support from the first position to the second position, when the electrical cable and the opening of the support are pressed towards each other, the electrical cable being located outside the loop, the handle comprising a substantially straight main part intended to be held by an operator, the handle further comprising an end part integral with the support and forming an obtuse angle with the main part, the end part forming the second external guide,