A solid state imaging device includes a pixel having a photoelectric conversion element formed on a semiconductor substrate. The photoelectric conversion element includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type formed on the first semiconductor layer and forming a junction therebetween; a third semiconductor layer formed on the second semiconductor layer and having a smaller band gap energy than the second semiconductor layer, the third semiconductor layer being made of a single-crystal semiconductor and containing an impurity; and a fourth semiconductor layer of the first conductivity type covering a side surface and an upper surface of the third semiconductor layer. Provision of the fourth semiconductor layer can reduce a current flowing in dark conditions.