Rogowski current sensor

Provided is a current sensor that, in a power semiconductor device, is capable of measuring current variations between chips and within a chip, defect discovery, and preventing failure. In a Rogowski current sensor having a return line path 2 that continuously connects a plurality of coils 1 along one closed line L and that is provided from the winding end of the last coil to the winding start side of the first coil of the plurality of coils 1, and detecting a voltage induced between the winding start side terminal of the first coil and the terminal of the return line path 2 as a function of the current in a circuit to be measured that is inserted inside the closed line L, each coil 1 that constitutes the plurality of coils 1 is formed on a plane perpendicular to the closed line L, among adjacent coils the space between the winding end of one coil and the winding start of the next coil is connected by an outbound line path 2 parallel to the closed line L, and the entire outbound line path 2 and the return line path 3 are arranged in proximity.