We report a flower-shaped micromotor driven by gliding bacteria named Mycoplasma mobile (M. mobile). This micromotor is autonomously rotated by the collisions of M. mobiles gliding randomly on a substrate. The flower-shaped rotor is derived from the unique motility of M. mobile. We examined the motility characteristics of M. mobile using walls with different corner angles. As a result, we found that M. mobile kept going at cusps. Owing to this property, the microrotor can be continuously rotated by random collisions of M. mobiles. In addition, we simulated the rotation of some kinds of microrotors with different number of blades. It was demonstrated that a microrotor with four blades could be stably rotated in experiments. The bacteria-driven micromotor will be applied to self-powered microsystems.