A solid-state imaging device comprising: a substrate; a plurality of photodetectors provided in an upper portion of the substrate and configured to perform photoelectric conversion; memories each provided for an associated one of the plurality of photodetectors in the upper portion of the substrate, and each configured to accumulate charge generated by the associated one of the plurality of photodetectors; at least one wiring layer provided above the substrate and including a plurality of metal wires formed therein; a first transparent insulating film provided in a region located directly above the photodetectors and between the plurality of metal wires, and penetrating the wiring layer; a transparent protective film covering the wiring layer and the first transparent insulating film, and having a higher refractive index than the first transparent insulating film; columnar first projections arranged on an upper surface side of the transparent protective film, each located above an associated one of the plurality of photodetectors, and each having a quadrilateral shape in top view; and a second transparent insulating film provided over the first projections, and having a lower refractive index than the first projections, wherein the wiring layer includes two or more wiring layers, and an interlayer insulating film which is made of the same material as the first transparent insulating film is provided between vertically adjacent two of the wiring layers wherein a plurality of cells are formed on the substrate, the cells each including one of the plurality of photodetectors and one of the memories that is associated with the one of the plurality of photodetectors, wherein the first projection has a height ranging from 5% to 30% of a width of the cell, and wherein a refractive index of the first projections is higher by 0.3 or more and 0.6 or less than that of the second transparent insulating film, characterized in that a length of one side of the shape in top view of the first projections ranges from 60% to 80% of the width of the cell. a substrate; a plurality of photodetectors provided in an upper portion of the substrate and configured to perform photoelectric conversion; memories each provided for an associated one of the plurality of photodetectors in the upper portion of the substrate, and each configured to accumulate charge generated by the associated one of the plurality of photodetectors; at least one wiring layer provided above the substrate and including a plurality of metal wires formed therein; a first transparent insulating film provided in a region located directly above the photodetectors and between the plurality of metal wires, and penetrating the wiring layer; a transparent protective film covering the wiring layer and the first transparent insulating film, and having a higher refractive index than the first transparent insulating film; columnar first projections arranged on an upper surface side of the transparent protective film, each located above an associated one of the plurality of photodetectors, and each having a quadrilateral shape in top view; and a second transparent insulating film provided over the first projections, and having a lower refractive index than the first projections, wherein the wiring layer includes two or more wiring layers, and an interlayer insulating film which is made of the same material as the first transparent insulating film is provided between vertically adjacent two of the wiring layers wherein a plurality of cells are formed on the substrate, the cells each including one of the plurality of photodetectors and one of the memories that is associated with the one of the plurality of photodetectors, wherein the first projection has a height ranging from 5% to 30% of a width of the cell, and wherein a refractive index of the first projections is higher by 0.3 or more and 0.6 or less than that of the second transparent insulating film, characterized in that a length of one side of the shape in top view of the first projections ranges from 60% to 80% of the width of the cell.