An elastic ring is disposed between a grip case and a trunk which is formed on an inner case of a body case to which a toothbrush head is mounted. As a result, the vibration of a motor which is contained in a motor accommodation portion of the inner case is less likely to be transmitted to the grip because of the elastic ring, and is transmitted to the toothbrush head side in a concentrated manner. Also, the tooth cleaning performance is increased, and vibration to the hand which grips the grip case is reduced to enable the user to comfortably brush the teeth.