The invention has as its object the provision of a medicine capable of reducing a volume of emphysema-suffering pulmonary alveoli or alveolar sacs by means of a respiratory region volume inhibitor containing a coating film formation as a main component and capable of forming a coating film in a respiratory region, characterized by being used in such a way that the coating film-forming component is administered to an emphysema-suffering pulmonary alveolar parenchyma in a human-respiratory region in an amount of 0.004 to 200 g/application, preferably 0.07 to 20 g/application and more preferably 0.5 to 5 g/application on each occasion.