Spontaneous pneumothorax is rarely occurred as an initial sign of primary lung cancer. As a lot of these cases have already advanced, even then surgical resection is performed, the prognosis is often undesirable, We happened to find a ruptured cavity on a 65-year-old male patient who had suffered from pulmonary tuberculosis in the past, while performing VATS bullectomy for simple spontaneous pneumothorax, Then, as a result of frozen biopsy, it was diagnosed as squamous cell cancer Because the tumor was infiltrated from the upper lobe into the lower lobe passing by fissure, we should remove by pneumonectomy and the pathologic stage was found stage I(T2N0M0). When we made an follow-up observation for one year and a half, there was neither relapse nor complication. When there appears spontaneous pneumothorax to the high risk group for lung cancer who were smokers over forty-year old, with chronic bronchitis or pulmonary emphysema, it needs to have a closer observation on a base lung disease such as lung cancer through chest CT, and it is also necessary to make more active approach by performing the surgical operation through a thoracoscopy when there is a continued air release.