A photoelectric conversion apparatus includes a plurality of pixels. Each of the plurality of pixels includes a first photoelectric conversion region and a second photoelectric conversion region. A first semiconductor region is disposed between the first photoelectric conversion region and the second photoelectric conversion region. The first photoelectric conversion region and the second photoelectric conversion region contain a first element mainly forming the first photoelectric conversion region and the second photoelectric conversion region, and the first photoelectric conversion region and the second photoelectric conversion region contain a second element. The first semiconductor region contains the first element and a third element. A mass number of the third element is twice or more a mass number of the first element.