Provided is an endoscope including an inserted portion that is inserted into a body, an observation optical system that is provided at a distal-end portion of the inserted portion and that acquires an image of the heart, and a supporting expansion portion that makes the heart support the distal-end portion of the inserted portion and that is provided with a basal-end-portion balloon, which is provided closer to a base-end portion than the distal-end portion of the inserted portion is, and a distal-end-portion balloon, which is provided so as to overhang forward from the distal-end portion of the inserted portion, wherein the base-end-portion balloon is disposed on the opposite side from the distal-end-portion balloon, with the inserted portion interposed therebetween.
