An ultraprecision rotary motor is developed using inchworm motion of two belts actuated by elongation of piezoelectric elements. A symmetric lever mechanism with flexure hinges is designed to connect belts with piezoelectric elements. The lever mechanism is used not only to amplify the elongation of piezoelectric element but also to minimize the numbers of components and the effort for assembly. By experiment, the rotational angle by one cycle is varied from $0.2{ imes}10-4 rad to 9.76{ imes}10-4$ rad depending on input signal amplitude. Further, the motor has the capability of getting more precise rotational resolution by enlarging the radius of the rotor.