We have been developing polymer actuators that have high performance and also have high productivity. The production process of this actuator is simple and employing common instrument. The displacement at 30 seconds after applying voltage 2.0 V was about 5 mm for 15 mm sample. The displacement is in proportion to the period of applying constant current. The output force is over 4 mN at 2.0 V. We also clarify a bending mechanism of our polymer actuator include bend back motion. The differences in size and in moving speed between cations and anions play a major role in bending mechanism. We also estimate the size and moving speed of each type of ions. These values are consistent with the measured displacement result.