An endoscope bending portion includes a circular cylindrical member on which a plurality of slots for bending are formed in a manner penetrating in a radial direction, a first slot among the plurality of slots for bending, a groove formed on the circular cylindrical member, a protrusion portion that is provided by being inserted into the circular cylindrical member through the groove from outside and by protruding on an inner circumference of the circular cylindrical member, where a wire hole is disposed inside the circular cylindrical member, a pulling wire that has a maximum outer diameter portion formed at a distal end portion, and that is inserted in the wire hole to have the maximum outer diameter portion engaged with the protrusion portion, and a restriction portion that is provided inside the circular cylindrical member.
