A mirror tilt actuator comprising: a mirror; a base; a mirror holder for holding the mirror; an elastic member for supporting the mirror holder movably relative to the base; and drive means for directing a reflected beam from the mirror to a desired direction by driving the mirror holder in response to a control signal to adjust the tilt angle of the mirror, wherein: the mirror tilt actuator has n plate springs as the elastic member, and m drive means as the drive means, n and m being integers of 2 or more; the n plate springs are arranged such that their surfaces are parallel to the reflection surface of the mirror and such that the plate springs are rotationally symmetric to each other about the center of the reflection surface of the mirror, and the n plate springs each have a section extending along the circumference of the mirror holder, the section being obtained by dividing the perimeter of the mirror holder substantially into n sections; the m drive means have cross-sections passing through the centers of the torque generated by the respective drive means which are on the same plane as the reflection surface of the mirror, and are arranged to be rotationally symmetric to each other about the center of the reflection surface of the mirror. a mirror; a base; a mirror holder for holding the mirror; an elastic member for supporting the mirror holder movably relative to the base; and drive means for directing a reflected beam from the mirror to a desired direction by driving the mirror holder in response to a control signal to adjust the tilt angle of the mirror, wherein: the mirror tilt actuator has n plate springs as the elastic member, and m drive means as the drive means, n and m being integers of 2 or more; the n plate springs are arranged such that their surfaces are parallel to the reflection surface of the mirror and such that the plate springs are rotationally symmetric to each other about the center of the reflection surface of the mirror, and the n plate springs each have a section extending along the circumference of the mirror holder, the section being obtained by dividing the perimeter of the mirror holder substantially into n sections; the m drive means have cross-sections passing through the centers of the torque generated by the respective drive means which are on the same plane as the reflection surface of the mirror, and are arranged to be rotationally symmetric to each other about the center of the reflection surface of the mirror. the mirror tilt actuator has n plate springs as the elastic member, and m drive means as the drive means, n and m being integers of 2 or more; the n plate springs are arranged such that their surfaces are parallel to the reflection surface of the mirror and such that the plate springs are rotationally symmetric to each other about the center of the reflection surface of the mirror, and the n plate springs each have a section extending along the circumference of the mirror holder, the section being obtained by dividing the perimeter of the mirror holder substantially into n sections; the m drive means have cross-sections passing through the centers of the torque generated by the respective drive means which are on the same plane as the reflection surface of the mirror, and are arranged to be rotationally symmetric to each other about the center of the reflection surface of the mirror.