A solid-state image pickup device 1 includes a semiconductor substrate 3A having a pixel array 10A with pixels arrayed in M rows and NA columns, a semiconductor substrate 3B having a pixel array 10B with pixels arrayed in M rows and NB columns, and a first column of which is arranged along an NA-th column of the pixel array 10A, and a signal output section 20. The signal output section 20 outputs digital values corresponding to the respective columns from the first column to the n-th column (2≦n