An endoscope includes: an insert portion having a bending portion for bending operation and a flexible soft portion connected to the proximal end of the bending portion; an inflatable/deflatable balloon attached on the proximal side from the bending portion; and a supplying/sucking opening provided in the outer surface of a ring that connects the bending portion to the soft portion, the supplying/sucking opening supplying and sucking fluid to and from the balloon.