In this paper, we described the development of an endoscopic system with the application of minimally invasive observation for a pituitary tumor or a craniopharyngioma. The end-effector was manufactured by attaching an image sensor to the end of a manipulator with a diameter of 3 mm (smaller than a commercial endoscope) by making slits on a biocompatible PAI (Polyamide-imide) tube. The end-effector having 2 degrees of freedom for bending is designed not only to cover most of the FOVs (92.8% of the goal) with commercially available fixed-angle endoscopes at 0, 30, and 70 degrees, but also to be able to maneuver the endoscope intuitively. The system consists of a controller, a foot switch, and the end-effector. Through qualitative experiments, basic verification of the proposed system was tested and the potential of this study was recognized through user evaluations from 3 specialists, which generated positive feedback upon the operational procedures.