A linear actuator, comprising: a yoke having a bottom surface and a side surface; a permanent magnet attached to the bottom surface of the yoke at a distance from the side surface of the yoke; a top plate attached to a top surface of the permanent magnet; a frame coupled to the yoke; a protector disposed on the frame; and a coil formed in a cylindrical shape and secured to the protector, the coil having a lower end positioned between the permanent magnet and the side surface of the yoke, wherein the actuator vibrates in a longitudinal direction of the coil due to the mutual electromagnetic force of the coil and the magnetic circuit composed of the yoke, the permanent magnet and the top plate, wherein the frame comprises a yoke coupling portion to surround and coupled to the outer periphery of the yoke for vibrating together with the yoke, a fixing portion spaced apart from the yoke coupling portion perpendicularly to a vibrating direction of the yoke coupling portion and coupled to the protector, and two or more bridges extended perpendicularly to the vibrating direction of the yoke coupling portion for connecting the yoke coupling portion and the fixing portion to be elastically deformed to support the yoke coupling portion of the frame during a vibration of the yoke coupling portion, characterized in that, the frame is injection-molded with an elastic material to surround and to be coupled to the outer periphery of the yoke, wherein the protector is composed of an injection-molded part securing the coil and a metal part, the metal part being insert-molded and coupled to the injection-molded part, wherein the metal part comprises a plurality of bent portions (424, 426, 428) coupled to the fixing portion configured to suppress vibration or deformation of the fixing portion. a yoke having a bottom surface and a side surface; a permanent magnet attached to the bottom surface of the yoke at a distance from the side surface of the yoke; a top plate attached to a top surface of the permanent magnet; a frame coupled to the yoke; a protector disposed on the frame; and a coil formed in a cylindrical shape and secured to the protector, the coil having a lower end positioned between the permanent magnet and the side surface of the yoke, wherein the actuator vibrates in a longitudinal direction of the coil due to the mutual electromagnetic force of the coil and the magnetic circuit composed of the yoke, the permanent magnet and the top plate, wherein the frame comprises a yoke coupling portion to surround and coupled to the outer periphery of the yoke for vibrating together with the yoke, a fixing portion spaced apart from the yoke coupling portion perpendicularly to a vibrating direction of the yoke coupling portion and coupled to the protector, and two or more bridges extended perpendicularly to the vibrating direction of the yoke coupling portion for connecting the yoke coupling portion and the fixing portion to be elastically deformed to support the yoke coupling portion of the frame during a vibration of the yoke coupling portion, characterized in that, the frame is injection-molded with an elastic material to surround and to be coupled to the outer periphery of the yoke, wherein the protector is composed of an injection-molded part securing the coil and a metal part, the metal part being insert-molded and coupled to the injection-molded part, wherein the metal part comprises a plurality of bent portions (424, 426, 428) coupled to the fixing portion configured to suppress vibration or deformation of the fixing portion.