Current sensor

A current sensor comprising:

• at least three bus bars that are made of flat-plate-shaped conductors that are provided side by side along a direction parallel to the thickness of the flat plate shape;
• a plurality of cores in which a core is formed by stacking flat plates made of U-shaped magnetic bodies and in which each of the bus bars is inserted into the inside a U-shaped U groove of the core formed by stacking the flat plates so that the face of the bus bar in a plate width direction and the face of a side wall inside the U-shaped U groove of the core formed by stacking the flat plates become parallel to each other;
• and
• a detecting element that is arranged on the side of an opening portion of each of the cores so that a detection direction thereof runs along a spacing direction of the opening portion and detects the intensity of a magnetic field,
• wherein the core is configured so that a gap between the core and another bus bar that is adjacent to the bus bar inserted into the U groove of the core as viewed in the axial direction of the bus bar becomes ½ of the length of the opening portion in the spacing direction, and
• wherein the tolerance of the gap is set to a value obtained by subtracting the value of 3/2 of the length of the opening portion in the spacing direction from the value of the interval between the bus bars that are adjacent to each other, with the gap as a median value.