PURPOSE: To prevent transfer to a cleaning process when a lid is not closed completely by a method wherein it is determined how a lid is closed by using a light emitting element and a light receiving element and the cleaning process is controlled accordingly.

CONSTITUTION: When an automatic cleaning operation switch is turned ON, a signal is sent to a light emitting circuit 7 of a lid closed state confirming device 5 so that a light emitting element 6 emits light. In this instance, if a lid 4 is not closed, a light receiving element 8 receives the light and the light signal is sent to a controller 9. The controller 9 determines that the lid is unclosed or not closed completely, a signal to stop a transfer to a cleaning process is sent to a cleaning device 3 so that cleaning by the cleaning device 3 is cancelled. To the contrary, when the light is cut off by the lid 4 and not received by the light receiving element 8, it is determined that the lid is closed completely, and a signal commanding the transfer to the cleaning process is sent. The cleaning device 3 receiving the signal comanding the transfer to the cleaning process from the controller 9, carries out the cleaning by injecting cleaning water from a cleaning nozzle 2 in a prescribed way in every nook and corner in a bath tub 1.