Abstract: Not only acute or chronic interstitial pneumonia and plumonary fibrosis but also chronic obstructive plumonary diseases, such as plumonary emphysema and chronic bronchitis, can be effectively prevented or treated by inhalation administration to the lung tissue of 2-{N-[4-(4-chlorobenzenesulfonylamino)butyl]-N-{3-[(4-isopropyl 2-thiazolyl)methoxy]benzyl}}-sulfamoylbenzoic acid or a pharmacologically acceptable salt thereof.