ABF-4 Fiber Bronchoscope is applied for observation, biopsy sampling, Bacteriology, Cytology diagnosis of lung, segment and sub-segment of patient’s bronchi. It can comply with photography, teaching and dynamic records while connection to TV system. With 4mm of outer diameter of insertion tube, it has good insertion performance. With 130°Up,90°Down of angulations and 85°of view of field, it can reach the position observed fast and correctly and then detect the diseases. With 25X magnifications, big depth of view and wide angle of view, and circle view of field, it can observe clear and vivid images within 3-50mm as well as small lesions never skipped.