Current measuring device for electric power lines, which comprises: at least one support body, having substantially planar form and provided with a external perimeter surface and with an internal perimeter surface, which at least partially delimits a through hole having an axis substantially orthogonal to said support body and intended to house at least one electric cable at its interior; - at least one solenoid winding made of conductive material, arranged on said support body and being extended around said through hole along a direction of extension that is substantially annular and symmetric with respect to the axis of said through hole; said support body and said solenoid winding being obtained by means of a printed circuit; said solenoid winding being organized in multiple groups of turns which: - are extended around said through hole for corresponding first arcs of circumference of said direction of extension, - are separated from each other by spacing sectors of said support body arranged alternately with said groups of turns along the direction of extension of said solenoid winding, - are connected together in series through electrical connections that pass through said spacing sectors, - are positioned substantially equally spaced apart from each other along the direction of extension of said solenoid winding; characterized in that said support body comprises a first flat support made of insulating material, preferably vetronite, on which the solenoid winding is obtained; said solenoid winding is formed by tracks provided on both faces of the first flat support, and by metalized holes obtained between the tracks of the two faces. at least one support body, having substantially planar form and provided with a external perimeter surface and with an internal perimeter surface, which at least partially delimits a through hole having an axis substantially orthogonal to said support body and intended to house at least one electric cable at its interior; - at least one solenoid winding made of conductive material, arranged on said support body and being extended around said through hole along a direction of extension that is substantially annular and symmetric with respect to the axis of said through hole; - at least one solenoid winding made of conductive material, arranged on said support body and being extended around said through hole along a direction of extension that is substantially annular and symmetric with respect to the axis of said through hole; said support body and said solenoid winding being obtained by means of a printed circuit; said solenoid winding being organized in multiple groups of turns which: - are extended around said through hole for corresponding first arcs of circumference of said direction of extension, - are separated from each other by spacing sectors of said support body arranged alternately with said groups of turns along the direction of extension of said solenoid winding, - are connected together in series through electrical connections that pass through said spacing sectors, - are positioned substantially equally spaced apart from each other along the direction of extension of said solenoid winding; - are extended around said through hole for corresponding first arcs of circumference of said direction of extension, - are separated from each other by spacing sectors of said support body arranged alternately with said groups of turns along the direction of extension of said solenoid winding, - are connected together in series through electrical connections that pass through said spacing sectors, - are positioned substantially equally spaced apart from each other along the direction of extension of said solenoid winding;