Hamartoma had been considered as a congenital malformation of a tumerous lesion since the original description by Albrecht in 1904. Pulmonary hamartoma is able to classified as endobronchial and intrapulmonary hamartoma clinically, and is considered to benign mesenchymal neoplasms which originated in peribronchial connective tissue, and so called mesenchymoma by someone. We have experienced 3 cases intrapulmonary hamartoma which were discovered during routine chest film check up at all cases and are able to detailed histologic examination by electron microscopy at one case