PURPOSE: To surely drive a lens with a simple structure, by arranging a disk type ultrasonic motor setting its center axis directing in a direction crossing orthogonal to the optical axis of a lens optical system, and driving the lens linearly directly by the tangential force of the rotation of the motor.

CONSTITUTION: When the motor is driven by a motor control circuit 17, a motor shaft 3a is rotated, and a lever 10 is rotated around the motor shaft 3a and a pin 11 fitting in both the groove part 10a of the lever 10 and the linear guide groove 12b of a lens barrel 12 is moved along a linear guide groove 12a, and moves a moving cylinder 16 in the direction of the optical axis. Thus, a focusing lens 15 is moved in the direction of the optical axis, thereby, a focusing state can be adjusted. Thus, by arranging the disk type ultrasonic motor so that its center axis can be directed in the direction crossing orthogonal to the optical axis of the lens optical system and driving linearly the focusing lens 15 directly by the tangential force of the rotation of the motor, focus adjustment is performed. In such a way, it is possible to surely perform the driving of the lens with the simple structure.