Photoelectric conversion apparatus and driving method thereof

A photoelectric conversion apparatus comprises a common signal reading line through which signals are read out from the photo receiving elements of a plurality of sensor chips. After sequentially reading out signals from a first photo receiving element included in a plurality of unit blocks to the common signal reading line, and before sequentially reading out signals from the photo receiving elements other than the first photo receiving element included in the same sensor chip to the common signal reading line, signals are read out to the common signal reading line from the photo receiving elements included in the unit blocks in the other sensor chips. Thus, a multi-chip type image sensor having a miniaturized chip size with desired performance is provided.