A semiconductor imaging device includes a photodetection region formed of a diffusion region of a first conductivity type formed in an active region of a silicon substrate at a first side of a gate electrode such that a top part thereof is separated from a surface of the silicon substrate and such that an inner edge part invades underneath a channel region right underneath the gate electrode, a shielding layer formed of a second conductivity type at a surface of the silicon substrate at the first side of the gate electrode such that an inner edge part thereof is aligned with a sidewall surface of the gate electrode at the first side, a floating diffusion region formed in the active region at a second side of the gate electrode, and a channel region formed right underneath said gate electrode, wherein the channel region includes a first channel region part formed adjacent to the shielding layer and a second channel region part formed adjacent to the floating diffusion region, wherein the second channel region part contains an impurity element with a concentration level lower than the impurity concentration level of the first channel region part.