A linear actuator includes a multipolar magnet configured such that an S pole and an N pole are linearly aligned in an alternating manner. The linear actuator also includes a coil body having a plurality of separate coil units integrally arranged in a lengthwise direction of the coil body, and being movable relative to the multipolar magnet. The linear actuator further includes a magnetic sensor that detects a position of the coil body along the lengthwise direction of the coil body with respect to the multipolar magnet, and an electrifying control circuit that individually controls currents to be supplied to the plurality of coil units based on the position of the coil body detected by the magnet sensor.