A linear actuator (1) comprises an electromagnetic block (10) which functions as an electromagnet, a plurality of magnetic blocks (20a, 20b) including a permanent magnet, and an output axle (30) which is disposed upon one of the plurality of magnetic blocks (20a, 20b). The plurality of magnetic blocks (20a, 20b) are disposed in parallel, and move reciprocally in an inverse phase when current is applied to the electromagnetic block (10) The output axle (30) has an axial direction of the reciprocal movement direction of the magnetic block.