A solid-state imaging device includes unit pixels formed on a semiconductor substrate. Each of the unit pixels includes a photoelectric converter, a floating diffusion, a pinning layer, and a pixel transistor. The pixel transistor includes a gate electrode formed on the semiconductor substrate, a source diffusion layer, and a drain diffusion layer. At least one of the source diffusion layer or the drain diffusion layer functions as the floating diffusion. The pinning layer is covered by the floating diffusion at a bottom and a side at a channel of the pixel transistor. A conductivity type of the floating diffusion is opposite to that of the pinning layer.