A linear actuator includes a driving part provided with an inner yoke and an outer yoke, a magnet disposed between the inner yoke and the outer yoke, and a movable body which is to be driven to reciprocate in the axial direction. The driving part includes a coil for generating an alternating magnetic field in a first gap space and a second gap space which are formed between the inner yoke and the outer yoke. The movable body is interlocked and driven with the alternating magnetic field. The driving part further includes a coupling means disposed along the axial direction in a gap space which is formed by the outer yokes adjacent to each other in a circumferential direction or by the inner yokes adjacent to each other in the circumferential direction. The coupling means connects the driving part to a main body part side which is provided with a moved body that is driven by the movable body.