To provide a manufacturing method of a spline piece gear low in manufacturing cost.

The manufacturing method of the spline piece gear by pressing a metal plate comprises a press drawing step of press-draw a center portion of a discoidal metal plate into a dish shape with a conical side circumferential portion, a chamfer forming process for forming chamfering a chamfer 60 extending in the radial direction on one side of a circumferential edge portion 40 surrounding the dish shape, a spline forming step for forming a spline portion having the chamfer 60 on a circumferential edge portion by punching a centrifugal end of the circumferential edge portion 40 including the chamfer 60, and a shaft hole portion forming step of forming a shaft hole portion 50 by punching a bottom of the dish shape. The spline piece gear can be manufactured without including any other step than the pressing step such as the cutting, and the manufacturing cost can be reduced thereby.