ELECTRIC CURRENT SENSOR

An electric current sensor includes first, second, and third current sensor modules, each including at least one bus bar formed in a rectangular shape extending in a width direction in cross section, to carry an electric current along a length direction perpendicular to the width direction, one pair of shield plates made of a magnetic material and disposed in a height direction perpendicular to the width direction and the length direction in such a manner as to sandwich the at least one bus bar therebetween, and at least one magnetic detection element disposed between the at least one bus bar and one of the one pair of shield plates, to detect a strength of a magnetic field in the width direction. The first, the second, and the third current sensor modules are arranged by superposition on top of each other in the height direction.