<p>Provided is a method for machining a tooth plane that is formed on a circumferential surface of a cylindrical toothed member and that extends along a center axis of the toothed member. The method includes: cutting the tooth plane by a peripheral cutting edge of an end mill while keeping a rotation axis of the end mill at a predetermined steady orientation and moving the end mill parallel to the center axis of the toothed member; rotating the toothed member by a predetermined angle around the center axis of the toothed member; and cutting the tooth plane by the peripheral cutting edge of the end mill while keeping the rotation axis of the end mill at the steady orientation and moving the end mill parallel to the center axis of the toothed member.</p>
