A photoelectric converting apparatus has first and third semiconductor layers of a first conductivity type which respectively output signals obtained by photoelectric conversion, and second and fourth semiconductor layers of a second conductivity type supplied with potentials from a potential supplying unit. In the photoelectric converting apparatus, the first, second, third and fourth semiconductor layers are arranged in sequence, the second and fourth semiconductor layers are electrically separated from each other, and the potential to be supplied to the second semiconductor layer and the potential to be supplied to the fourth semiconductor layer are controlled independently from each other.