An inserting portion has, at the proximal end thereof, an operating portion having a bending lever for bending operation. The operating portion has, on the front end side thereof, a grip portion gripped by an operator. The grip portion has therein a plate frame as an internal structure for ensuring predetermined strength. At the notch portion formed by partly notching the frame, an image pick-up unit is mounted to form an optical image transmitted by image guiding fibers to a CCD via a relay optical system. The image pick-up unit is fixed to the frame via an attaching member. Thus, predetermined strength is assured and the image pick-up unit is compactly accommodated with simple structure. A predetermined image pick-up function using the image pick-up unit is held without the action of high tension to the image guiding fibers by mounting a bending portion to the image guiding fibers.