A semiconductor manufacturing method includes forming a first metal film on a semiconductor wafer by plating, ejecting liquid from a washer bar spaced from the wafer while rotating at least one of the washer and the semiconductor, and forming a second metal film on the first metal film. A plurality of nozzles are located on the washer bar and displaced from the position of the washer bar opposed to the center of the wafer, and a greater number of nozzles are adjacent the peripheral area of the semiconductor wafer than the central area of the semiconductor wafer. The nozzles in the peripheral area of the wafer eject the washing liquid in a direction inclined from the direction of the washer bar, and a nozzle arranged on the central area of the one main surface of the semiconductor wafer ejects the washing liquid towards the center position of the semiconductor wafer.