This invention provides a polymer actuator having a structure such that voltage can be efficiently applied to two or more actuator electrodes without directly providing an electrical contact point to an expanding and contracting portion.An actuator has: an insulating base material 1; a first terminal 2 for energizing provided contacting the insulating base material; a first actuator electrode 4 provided contacting the first terminal; an electrolyte layer 5 provided contacting the first actuator electrode; a second actuator electrode 6 provided contacting the electrolyte layer; a second terminal 3 for energizing provided spaced apart from the first terminal and contacting the insulating base material; an energization preventing portion 7 for preventing energization of the first terminal and the second terminal; and a connecting portion 8 provided contacting the energization preventing portion in order to energize the second actuator electrode and the second terminal.