A downsized current sensor with a switch function is disclosed. The current sensor includes: a magnetic circuit to converge a magnetic flux generated from an electric circuit at a magnetic sensor; a switch to open and close the electric circuit in a way that operates together with a movable magnetic body configuring a part of the magnetic circuit; and a magnetizing coil to generate magnetic force enabling the movable magnetic body to be attracted to a fixed magnetic body configuring a part of the magnetic circuit.