The present invention provides a manufacturing method for an impeller with which molding and high-quality finishing can be performed extremely easily and quickly through resin molding using a die, and an impeller manufactured by the impeller manufacturing method. A metallic bush is disposed in a die, whereupon a resin material is injected through a gate in the die. A connecting portion between an unnecessary resin portion formed from residual resin material in the gate and a resin impeller main body molded around the bush is formed to be thin, and the unnecessary resin portion is removed from the impeller main body using pushing or withdrawing means.