Abstract: An actuator is provided that includes: a diaphragm that vibrates to generate sound; a housing that is attached to an outer edge of the diaphragm to support the diaphragm; an accommodating space that is formed inside the diaphragm and the housing, and an axis of which extends in a thickness direction of the diaphragm in the middle of the diaphragm; a coil that is wound around the axis, is attached to a face of the diaphragm facing the accommodating space, and is disposed in the accommodating space; a movable body that is disposed in a radial inside space of the coil or on an extension of the space, within the accommodating space; and a spring that supports the movable body such that the movable body is movable in the axial direction within the accommodating space.