PROBLEM TO BE SOLVED: To reduce droplets remaining on a ceiling and residual water in a washing tub resulting from them at the point of time of ending water discharge without extending the total time of a rinsing step in the case of washing the ceiling of a top cover.SOLUTION: In the washing tub of the washing and disinfecting device, an upper opening is covered with the top cover. A ceiling washing nozzle for spraying liquid toward the ceiling which is the inner surface of the top cover is provided in the inside of the washing tub. In the rinsing step, water inside the washing tub is circulated by a circulation pump 76. A valve 92 is arranged in a supply route connecting the circulation pump 76 and the ceiling washing nozzle, and at the start of circulation, the valve 92 is opened and the water is sprayed from the ceiling washing nozzle. The valve 92 is closed when spray time T1 has elapsed since the start of the circulation and the spray of the ceiling washing nozzle is stopped. When the circulation is ended, the water is drained. A long period of time during which the water falls from the ceiling by gravity is secured without prolonging the time for draining water.
