A solid-state imaging device is provided with picture elements which are each composed of a photoelectric conversion element and a MOS transistor as a switching element and which are arranged in the form of a matrix. A scanning mechanism sequentially scans the picture elements to sequentially read out photoelectric conversion signals. To eliminate smear and reduce parasitic capacitance, a high-impurity-concentration diffusion layer serving as an output terminal of the MOS transistor constituting the picture element is formed on an insulator layer for isolating the elements.
