A solid-state image sensor for a solid-state image pickup apparatus includes photosensitive cells each having a photosensitive area divided into a main region and a subregion. The subregion is extended to include the position of a virtual pixel. A light-screening layer is formed with optical openings corresponding to the main and subregions, so that light is incident not only to the main region or actual pixel but also to the subregion at the position of the virtual pixel. Spatial information is therefore available even at the position of the virtual pixel in the form of a signal charge.