An elbow manufacturing method characterized in comprising: a first cutting step for cutting the material by moving a cutting section, which is formed from at least a portion of a roughly spherical cutting tool, relative to the material in a direction from a first end face to a second end face of the material along the inner surface of the intended finished elbow; and a second cutting step for cutting the material by moving the cutting section relative to the material in a direction from the second end face to the first end face of the material along the inner surface of the intended finished elbow.