Provided is a solid-state imaging device including: a photodiode which converts an optical signal to signal charges; a transfer gate which transfers the signal charges from the photodiode; an impurity diffusion layer to which the signal charges are transferred by the transfer gate; and a MOS transistor of which a gate is connected to the impurity diffusion layer. The impurity diffusion layer has a first conduction type semiconductor layer and a second conduction type semiconductor layer which is formed in the first conduction type semiconductor layer and under an end portion of the transfer gate.