An actuator includes a sheet having dielectric elastomer layers and conductive rubber layers provided on the front and back faces of each dielectric elastomer layer. The sheet is wrapped and rolled about a coil spring. The actuator expands the rolled sheet along an expansion direction of the coil spring by applying a voltage to the conductive rubber layers on the front and back faces of the dielectric elastomer layer, and contracts the rolled sheet along a contraction direction of the coil spring by stopping the application of the voltage. The actuator further includes a fiber layer located between the coil spring and the rolled sheet wrapped about the coil spring.