A manufacturing method of an impeller, the manufacturing method includes: a step of forming an impeller shaped body in which a disc component part constituting a part of the disc, a blade component part constituting a part of the blade, and a cover component part constituting a part of the cover are integrated by laminating a metal layer to extend toward an outer side in a radial direction with respect to the axis by an additive manufacturing method using a metal powder; and a step of grinding the impeller shaped body, in which the steps are repeated a plurality of times, and the step of grinding the impeller shaped body includes a step of polishing an inner surface of the impeller shaped body constituting a part of the flow path.