Abstract: An oral cavity cleaner including a pump unit for supplying a pulsating stream of high-pressure fluid, and a toothbrush unit connected thereto via a flexible conduit. The toothbrush unit includes an actuating member responsive to the pressure of the pulsating stream of fluid to provide a reciprocatory movement, a toothbrush connected to the actuating member, a valve section brought to an open position when the movement of the actuating member has exceeded a predetermined value, and an operating member for operating the valve section. The toothbrush can be automatically given a reciprocatory movement, and the high-pressure fluid can be ejected through the toothbrush or its ejection can be stopped as desired by manipulating the operating member while the toothbrush is being moved with a reciprocatory movement.