A bending portion includes: a bending piece set in which a plurality of bending pieces are continuously provided by forming a convex portion on a first bending piece and a concave portion on a second bending piece by cutting a rigid pipe, the convex portion and the concave portion forming an engagement portion that pivotably couples adjacent bending pieces to each other, wherein a first engagement portion includes: a first convex portion formed on the first bending piece and including a first peripheral portion serving as a first pivoting surface and a first concave portion formed on the second bending piece and including a first inner circumferential portion on which the first peripheral portion slides, and the first engagement portion has, in the first peripheral portion, a tapered surface having an outer diameter that becomes smaller from a bending piece inner surface side toward a bending piece outer surface side.