A method of manufacturing a semiconductor device, the semiconductor device comprising: a semiconductor substrate; a pixel portion including an in-layer lens; and a peripheral circuit portion including a metal wiring portion, the pixel portion and the peripheral circuit portion being on the semiconductor substrate, the method comprising: forming an insulating film in the pixel portion and the peripheral circuit portion, so as to cover the metal wiring portion; providing, on the insulating film, a lens material layer for forming the in-layer lens; forming a resist layer for etching the lens material layer; curing the resist layer; and forming a first region and a second region in the resist layer, wherein a portion of the resist layer in the first region is thicker than that of the resist layer in the second region, the first region being in the peripheral circuit portion and the second region being in the pixel portion.