A micromirror actuator having a micromirror, which is operative using an electrostatic force with a low voltage and wherein an electrostatic force opposite to the driving force of the micromirror is blocked, and a method for manufacturing the same, are provided. The micromirror actuator includes a substrate, a trench in which at least one electrode is formed, supporting posts installed at opposite sides of the trench, a torsion bar supported by the supporting posts, and the micromirror including a driving unit which faces the trench when the micromirror is in a horizontal state, and a reflecting unit, which is elastically rotated about the torsion bar, to reflect an optical signal. The actuator also includes a shielding electrode installed to face the reflecting unit when the micromirror is in a horizontal state and to block an electrostatic force occurring between the reflecting unit and the electrode.