Conventionally, it is impossible to water a potted plant or the like with a freely moving cleaner. A cleaner of this invention finds a travel route to the location of a first potted plant said cleaner determines that current time is a timer-set time, travels to said location to pour a specified amount of water on said potted plant, on completion of that watering finds a travel route to a second potted plant, travels to said location, pours a specified amount of water on said second potted plant, and on completion of that watering returns to an initial standby position at a hall.