An imaging device includes pixels, output lines on each column, an AD conversion unit including column AD conversion circuits connected to the output lines, a first storage unit including holding units connected to the column AD conversion circuits, a transfer unit that transfers signals in the first storage unit, a second storage unit that holds signals from the transfer unit, and an output unit that outputs signals in the second storage unit. The pixels output a first analog signal based on signal from the first photoelectric converter and a second analog signal based on signal from the first and second photoelectric converter. The AD conversion unit converts the first and second analog signals into first and second digital signals. The number of signals corresponding to the first digital signals of signals output by the output unit is less than the number of signals output in parallel from the output lines.