A MOS solid-state imaging device is provided in which withstand voltage and 1/f noise of a MOS transistor are improved.In the MOS solid-state imaging device whose unit pixel has at least a photoelectric converting portion and a plurality of field effect transistors, the thickness of gate insulating film in a part of the field effect transistors is different from the thickness of gate insulating film in the other field effect transistors among the plurality of the field effect transistors.