N.sup.+-type semiconductor regions 12d are formed on a front surface side of a p.sup.--type layer 12c of a semiconductor substrate 12, and these n.sup.+-type semiconductor and p.sup.--type semiconductor constitute photodiodes. A metal wire 14 connected to an isolation region 12e is formed on a first insulating layer 13. The metal wire 14 is provided so as to extend along a row direction and along a column direction between adjacent n.sup.+-type semiconductor regions 12d, and is of grid shape when viewed from a direction of incidence of light. Signal readout lines 53 are formed on a third insulating layer 16. The signal readout lines 53 are made of metal such as aluminum, are located above the n.sup.+-type semiconductor regions 12d when viewed from the direction of incidence of light, and are provided so as to extend along the column direction.