A current sensor includes a first current path including a first flat-shaped portion, and a first magnetoelectric conversion element arranged on the first current path and configured to detect magnetism generated when a current to be measured flows through the first current path, wherein the current sensor measures the current to be measured of a device to which the first current path is connected, a first conductive convex portion is provided, in the first current path, in a direction in which the current to be measured flows, and the first magnetoelectric conversion element is arranged at a position on the first current path, at which a magnetic flux density due to the current to be measured of a minimum frequency used in the device and a magnetic flux density due to the current to be measured of a maximum frequency used in the device substantially coincide with each other.