The invention relates to a cleaning container (12) comprising an inlet (120) which is connected to the water container (11), and an outlet for connecting a suction tube (43), the outlet (122) being embodied as a hydrant (124) for a suction handpiece (42) applied to the suction tube (43). The cleaning container (12) can be filled with the water from the water container (11) especially by means of a negative pressure applied to the outlet when the suction tube (43) is connected.