When the conductive high-molecular membrane portion (101,1501) with the electrode (104,1504) with the electrolytic section (102,1502,1512) with the actuator which it has (89) with, impressing voltage in the conductive high-molecular membrane portion and between the electrodes, it detects the displacement tonnage of the actuator by detecting the ripple mark of the electric current which flows, impressing voltage in the conductive high-molecular membrane portion on the basis of the displacement tonnage which is detected, it adjusts the displacement tonnage of the actuator.導電性高分子膜部(101,1501)と電極(104,1504)と電解質部(102,1502,1512)とを備えるアクチュエータ(89)と、導電性高分子膜部と電極の間に電圧を印加したときに流れる電流の波形を検出することによりアクチュエータの変位量を検出し、検出した変位量に基づいて導電性高分子膜部に電圧を印加してアクチュエータの変位量を調整する。
