A load sensor is provided with a pressure-receiving core made of a magnetostrictive material on which a load to be detected acts, a non-pressure-receiving core made of a magnetic material concentrically arranged with the pressure-receiving core and on which the load to be detected does not act, a detection coil that generates a magnetic flux that passes through the pressure-receiving core by energizing, and a reference coil that, when energized, generates a magnetic flux that does not pass through the pressure-receiving core but passes through the non-pressure-receiving core.