A method of manufacturing a semiconductor device is disclosed, wherein a plating layer is formed on a first surface side of a semiconductor substrate stably and at a low cost, while preventing the plating liquid from being contaminated and avoiding deposition of uneven plating layer on a second surface side. An electrode is formed on the first surface of the semiconductor substrate, and another electrode is formed on the second surface. A curing resin is applied on the electrode on the second surface and a film is stuck on the curing resin, and the curing resin is then cured. After that, a plating process is conducted on the first surface. The film and the curing resin are then peeled off.