A magnetic sensor has a Hall IC that has a Hall element formed on a surface of the Hall IC, and a lead frame that supports the Hall IC. The lead frame includes a first region that is disposed in the vicinity of the Hall element and generates a first magnetic field due to a first eddy current generated when a measurement target magnetic field is applied, and second regions that are disposed away from the first region and generate a second magnetic field having an intensity that cancels the first magnetic field by means of second eddy currents generated when the measurement target magnetic field is applied.