MICROMIRROR DEVICE AND OPTICAL SCANNER

To provide a micromirror device that is small-sized and can increase the deflection angle of a mirror part in gas, and provide an optical scanner.SOLUTION: A micromirror device comprises: a movable part that has a mirror part provided with a reflection surface reflecting incident light; a first support part that is connected with the movable part on a first axis located in a plane including the reflection surface when the mirror part is stationary and supports the movable part swingably around the first axis; and a pair of first actuators that are connected with the first support part and opposite to each other across the first axis, the first actuators of a piezoelectric driving system swinging the movable part around the first axis. When the movable part swings around the first axis, at least part of the first actuators swings in an opposite phase to that of the movable part around the first axis. When the ratio of the rotation angle of the first actuators to the rotation angle of the movable part is R, 0