To provide a small-sized and easily carriable and handleable water supply/discharge function.

By supplying air from an air pump 4a for water supply to a water supply tank 2 and turning the water supply tank 2 to a pressurized state, water is supplied from the water supply tank 2 to a toothbrush main body 1. By sucking the air from a water discharge tank 3 by the air pump 4b for water discharge and turning the water discharge tank 3 to a pressure reduced state, the water is sucked from a mouth and is discharged. Also, by using the air pump for both supplying and discharging the air and sending the air sucked from the water discharge tank 3 to the water supply tank 2 while sucking the air of the water discharge tank 3, the water supply tank 2 is turned to the pressurized state and the water is supplied from the water supply tank 2 through a water supply path 12 of the toothbrush main body 1 to the mouth. Also, by turning the water discharge tank 3 to the pressure reduced state, the water is sucked and discharged from the mouth through a water discharge path 14 of the toothbrush main body 1.