There is provided an actuator element which can be driven at low voltages, is operated stably in air and in vacuo with a quick response, exhibits a large degree of displacement and a large displacement force, has high mechanical strength including flexibility, thus giving long-term durability for repeated use, can be produced by a very simple method, can be formed into a small size because of a simple structure, and can be put into practical use in wide applications. The actuator element is comprised of an ion-conducting layer for an actuator element comprising (I) a fluorine-containing polymer having functional group and (II) an ionic liquid, in which the fluorine-containing polymer having functional group is a polymer having functional group selected from the group consisting of -OH, -COOH, -COOR, -CN, iodine atom, epoxy group and (meth)acryloyl group in a polymer side chain and/or at an end of a polymer trunk chain, and an electrode layer comprising (I) the fluorine-containing polymer having functional group, (II) an ionic liquid and (III) an electroconductive nano-filler.