A solid-state image pickup device and a camera system in which: (1) counters are organized into a counter group and a memory group on a column-by-column basis; (2) in each column, the individual counters are cascade-connected between individual bits; (3) switches are provided at bit output portions of the individual counters; (4) connecting sides of the individual switches are commonly connected to a column-signal transfer line, and output sides of the switches are shared with the other individual bits; (5) inputs of memories (latch circuits), which store digital data for horizontal transfer, share the column-signal transfer line; and (6) outputs of the memories corresponding to the individual bits are connected via switches to data transfer signal lines wired so as to be orthogonal to the column-signal transfer line.