An oral cavity washing device includes a body unit including a pump for discharging a washing liquid, a tube connected to the body unit for making the washing liquid discharged from the pump flow through the tube, and a washing unit connected to the tube for discharging the washing liquid. The oral cavity washing device further includes a joining portion which joins the body unit and the washing unit to each other by a magnetic force. With such a configuration, it is possible to provide an oral cavity washing device where the washing unit can be easily mounted on the body unit.
