An endoscope main body constituting an endoscope in a state in which an elongated detachable observation optical system is attached to the endoscope main body, and in a proximal end of an insertion section of the endoscope main body, a branch member is disposed. The branch member is provided so that a first extended section and a second extended section are branched from each other and thereby first and second operating sections are separately arranged. Furthermore, the branch member has an opening as an inlet which guides an imaging module in a distal end of the observation optical system to a hard portion of the insertion section.
