At present, one-piece tube bodies are mostly used as insertion parts of conventional endoscope apparatuses for the accommodation of printed circuit boards that are connected with image capture modules and light-emitting modules. However, as the tube diameters of endoscopes are trending towards smaller sizes, there occurs a problem that it is more and more difficult to assemble printed circuit boards, image capture modules and light-emitting modules in conventional endoscopes. Particularly in endoscope apparatuses that capture images with two angles of view, due to their higher structural complexity compared to endoscopes providing a single angle of view, the difficulty will increase as endoscopes are trending towards smaller sizes. Therefore, with more and more stringent requirements for the tube diameters of endoscopes, it is quite urgent and important to provide an endoscope apparatus having a small tube diameter and suitable for providing two angles of view even multiple angles of view.