According to one embodiment, a solid-state imaging device includes a pixel region which is configured such that a photoelectric conversion unit and a signal scanning circuit unit are included in a semiconductor substrate, and a matrix of unit pixels is disposed, and a driving circuit region which is configured such that a device driving circuit for driving the signal scanning circuit unit is disposed on the semiconductor substrate, wherein the photoelectric conversion unit is provided on a back surface side of the semiconductor substrate, which is opposite to a front surface of the semiconductor substrate where the signal scanning circuit unit is formed, and the unit pixel includes an insulation film which is provided in a manner to surround a boundary part with the unit pixel that neighbors and defines a device isolation region.