To provide an image pickup apparatus capable of adding signals from a plurality of photoelectric conversion portions, an image pickup apparatus including a plurality of unit cells arranged in an array, each unit cell including a plurality of photoelectric conversion portions and a common circuit for inputting signals from the plurality of photoelectric conversion portions and outputting the signals from the unit cell, a first addition circuit for adding the signals from the plurality of photoelectric conversion portions in the unit cell, and a second addition circuit for adding the signals from the plurality of photoelectric conversion portions outside the unit cell is provided.