Method of manufacturing semiconductor device

To provide a semiconductor device capable of having improved adhesion between a plating film and a wiring layer. A method of manufacturing the semiconductor device includes a step of forming a wiring layer having a surface covered with an oxide film, a step of removing a portion of the oxide film by dry etching to form, in the oxide film, a first opening for exposing a portion of the wiring layer, a step of forming a passivation film covering the wiring layer, is provided with a second opening communicated with the first opening, and is made of an insulating resin material, and a step of growing a plating film on the wiring layer exposed from the first and second openings.