A method of manufacturing a semiconductor device includes: forming a mask layer on a layer that is to be subjected to etching and contains at least one of silicon carbonate, silicon oxide, sapphire, gallium nitride, aluminum gallium nitride, indium gallium nitride, and aluminum nitride, the mask layer having an opening and including a nickel chrome film, a gold film, and a nickel film in this order when seen from the layer to be subjected to etching; and performing etching on the layer to be subjected to etching, with the mask layer serving as a mask.