A current sensor includes: a current bar through which a current flows; a first cover that covers the current bar and includes a cutout portion formed in at least a part thereof; a magnetic substance core that covers at least parts of the current bar and the first cover and includes a gap; a magnetic field measuring element located in the gap; and a second cover that covers the magnetic substance core and the magnetic field measuring element and at least parts of the current bar and the first cover, and is located so that a side surface thereof engages with the cutout portion of the first cover.