To increase the tilt angle of a mirror without increasing the element side of a thin film type optical modulator.

The thin film optical modulator having actuators formed by having deformation layers on supporting layers 111 and light reflecting means (mirrors 150) formed in the upper parts of the supporting layers is arranged with the actuators by aligning the longitudinal direction of the actuators to the diagonal direction of the light reflecting means. The length of the actuators may be made longer without changing the element sizes by adopting such arrangement and consequently, the tilt angle of the mirrors 150 formed thereon may be made larger.