Provided are an endoscope with an insertion portion. The insertion portion is flexible and inserted into a body cavity and is provided with a bend provided at its front end side, wherein a plurality of ring shaped bend blocks which can be freely and rotationally connected by a joint portion with a pivotally supporting portion and a pivot portion is arranged in the bend, a peripheral portion of an opposition surface opposite to the adjacent bend blocks is made to be a butt portion and is butted to define the curvature radius to be bent maximally, so that the maximum bend is carried out in a first curvature radius, the four bend operation lines crossing the insertion portion is pulled/loosened so as to make the bend to bend towards four directions; a first flexible tube section provided continuous to the proximal end of the bend, wherein a plurality of ring shaped curvature defining blocks which can be freely and rotationally connected by the joint portion with the pivotally supporting portion and the pivot portion is arranged in the first flexible tube section, the peripheral portion of an opposition surface opposite to the adjacent curvature defining blocks is made to be the butt portion and is butted to define the curvature radius to be bent maximally, so that the maximum bend is carried out in a second curvature radius larger than the first curvature radius; and a second flexible tube section composed of a spiral tube, a braid coating the spiral tube periphery and a sheath coating the braid, which has larger bend rigidity than that of the first flexible tube section of the insertion portion, and is provided continuous to the proximal end of the first flexible tube section. The curvature radius of the first flexible tube section that is passively bent by a predetermined amount of force when the bend and the first flexible tube section pass a tortuous section in the body cavity is set greater than the curvature radius of the bend that is bent.