To provide a macromolecule actuator which can realize more suitable operation, while taking account of durability, response, and the like.

The macromolecule actuator 100 includes counter electrodes 102 and 103 on the surface of a substrate 101 made of ion-exchange resin. The output from a drive voltage source 202 is applied to the electrodes 102 and 103 via an electrode pad 201. When a negative voltage is applied to a left side electrode 102 and a positive voltage is applied to a right side electrode 103, cations and polar molecules in the substrate 101 move to the cathode side by the electric field generated by the applied voltage, and the cathode side swells, as compared with the anode side and thereby the tip of the substrate 101 is deformed to the right side in the figure. When a negative voltage is applied to a right side electrode 103 and a positive voltage is applied to a left side electrode 102, the action is reversed and the tip of the substrate 101 is deformed to the left side. The macromolecule actuator 100 is driven by utilizing such characteristics.