Metallic glasses(MG) are amorphous structured metallic materials and exhibit excellent mechanical properties and materials functions such as wear resistance. The materials are favorable materials for manufacturing various miniature machine parts and MEMS/NEMS by micro/nanoforming or nanoimprint with dies by precision casting and superplastic forming. We have developed micro geared motors of 2.4 mm, 1.5 mm and 0.9 mm in diameter. The geared motor consists of a coreless motor and a planetary gear head. The 4-stage planetary gear head is composed of an internal gear, an output carrier, twelve planetary gears and three sun carriers. A conventional sun carrier was assembled of five individually machined parts such as a sun gear, a carrier plate and three pins. In the present study, metallic glasses have been applied to fabricate the sun carrier by precision die casting. The cast sun-carrier has not only high strength of the material but also high structural rigidity due to its uniform construction by casting. The worn loss of the cast MG micro gears is much smaller than that of conventional steel micro gears. Consequently, the performance and lifetime of the world smallest micro geared motors have been remarkably improved. With decreasing the dimension of a geared motor, the machine components have been fabricated in good accuracy of dimension. Superplastic die forging and hob cutting method have been applied to fabricate small gears for the microgeared motor of 0.9 mm in diameter. The developed geared motors are powerful micro drivers and are useful for various applications.