A micro manipulator for electrode movement, a driving method thereof, and a brain signal measuring device using the same are provided. The micro manipulator has a guide member having a rectangular hollow hole therein, first and second piezo-electric clamp bodies installed perpendicular to the movement direction of the electrode between the inner opposite sides in the hollow hole of the guide member such that respective both ends thereof are selectively fixed to or separated from the inner sides of the hollow hole depending upon whether of the application of electric power thereto, a drive piezo-electric body whose both ends are connected to the opposite faces, respectively, of the first and second clamp piezo-electric bodies to selectively expand or contract in parallel with the movement direction of the electrode depending upon whether of the application of electric power thereto, and an electrode holder holding therein the electrode and installed on the first or second clamp piezo-electric body in parallel with the expansion or contraction direction of the drive piezo-electric body.