A 76-year-old man who was being treated for bronchial asthma and pulmonary emphysema by his family physician experienced dyspnea and was referred to our department with suspected pneumonia. The patient responded poorly to sulbactam/cefoperazone and clarithromycin. A cavity lesion appeared in the left upper lobe, Aspergillus was detected from his purulent sputum, and an Aspergillus fumigatus-precipitating antibody was seen. Therefore, chronic necrotizing pulmonary aspergillosis was diagnosed. Blood tests showed elevated levels of eosinophils and serum IgE, and Aspergillus-specific IgE was detected. Following the administration of micafungin and itraconazole, the cavity lesion diminished in size, and his eosinophil and serum IgE levels decreased. The patient was believed to have had chronic necrotizing pulmonary aspergillosis accompanied by allergic reactions to Aspergillus.