A cleaning device and a cleaning method for cleanly and thoroughly cleaning the outer surface and the inner surface of a bag-like article. A support column (2) has a first air nozzle (3) for ejecting air to the inside of a bag-like article (G), a first chemical liquid nozzle (4) for ejecting chemical liquid, a second air nozzle (6) for ejecting air to the outer surface of the bag-like article (G) supported by the support column (2), and a second chemical liquid nozzle (7) for ejecting the chemical liquid. A blower (10) for supplying air and a heater (11) for heating the air supplied are connected to the first air nozzle (3) and the second air nozzle (6). A chemical liquid supply pump (20) is connected to the first chemical liquid nozzle (4) and the second chemical liquid nozzle (7), and tanks (21, 22) for containing strong alkali electrolysis water or strong acid electrolysis water as the chemical liquid are connected to the pump (20). The bag-like article is cleaned while being floated by pressure of air ejected from the first air nozzle (3) of the support column (2), and this enables the inner surface of the bag-like article to be completely cleaned.