To provide a small oral cavity washing device efficiently washing inside the oral cavity without injuring the oral cavity mucosa, surely sucking sputum and foreign matters in the oral cavity and being easily handled.

This oral cavity washing device is provided with a cleaning head 2 which has a washing feed pipe 3 feeding washing to the inside of the oral cavity, and a waste water suction pipe 4 sucking the waste water from the oral cavity. This device is so constituted that the cleansing head 2 is provided with a cleaning member 5 composed of a permeable porous material, the cleaning member 5 is formed with a through-hole 51, the waste water suction pipe 4 is inserted in the through-hole 51 and an opening 57 of the waste water suction pipe 4 communicates with the outside.