A linear actuator that is configured to be extended/contracted by relatively displacing a first tube and a second tube in an axial direction, includes a rod that is provided inside the first tube, a plurality of permanent magnets that are held in the rod so as to be arranged in the axial direction; a stopper that is provided on a tip-end portion of the rod, a coil that is provided inside the second tube so as to face the permanent magnets, and a stopper receiving portion that is provided on the second tube so as to face the stopper, wherein the relative displacement between the first tube and the second tube in the extension direction is restricted by bringing an extension-direction-side end surface of the stopper into contact with the stopper receiving portion at a fully extended position.