To provide a satisfactory polishing effect with a small turning force motor in a toothbrush.

A cylindrical brush 1 planting spirally a few bristles therein is rotated by a motor 2 in a motor brush. The motor toothbrush can polish teeth along parts between the teeth c drawing a circular track perpendicular to the polished surface by the rotation of the motor 2 received in a stem 7 constituted from a cover 6 uniting a bearing 4 supporting the cylindrical brush 1 and a hollow shaft 5. A drive mechanism is provided which eliminates the stop phenomenon and vibration of the bristle tip b, further has a sharp polishing effect such as preventing the uneven polishing and scaling out residual food and sordes on teeth.