The invention provides an electric toothbrush capable of changing a resonant frequency and vibration amplitude of an eccentric shaft. An electric toothbrush of the present invention includes a motor, an eccentric shaft with one end fixed to a rotation shaft of the motor, and a stemserving as a vibration transmitting component having a bearing for supporting the other end of the eccentric shaft for transmitting vibration generated in accordance with rotation of the eccentric shaft to a brush portion. In the electric toothbrush, the eccentric shaft is formed so that a gravity center position is movable at least in one direction among a direction in which a distance to a shaft center is changed and an axial direction.
