A photoelectric conversion element, comprising: a depletion-layer extension-promotion region having an upper layer of a first conductivity type; a photoelectric conversion layer of the first conductivity type in contact with the upper layer of the depletion-layer extension-promotion region , having a lower impurity concentration than the upper layer; a surface-buried region of a second conductivity type buried in a part of an upper portion of the photoelectric conversion layer , configured to implement a photodiode together with the photoelectric conversion layer ; a well region of the first conductivity type buried in another part of the upper portion of the photoelectric conversion layer , having higher impurity concentration than the photoelectric conversion layer ; a charge-accumulation region of the second conductivity type buried in a part of an upper portion of the well region , configured to accumulate signal charges temporally; a plurality of intra-pixel circuit-elements merged in a part of the well region , configured to implement a circuit for reading out the signal charges from the charge-accumulation region ; and an injection-blocking element having a tab-region of the second conductivity type dividing the well region into no less than two at least at a part of the well region , configured to block injection of non-signal charges having opposite conductivity type to the signal charges from the well region into the photoelectric conversion layer by a potential profile generated by a junction between the tab-region of the second conductivity type and the well region of the first conductivity type, wherein an entire range intended as a signal-charge generation-region in the photoelectric conversion layer is depleted by a voltage applied to the upper layer, with aid of the relative impurity concentrations of the photoelectric conversion layer and the upper layer . a depletion-layer extension-promotion region having an upper layer of a first conductivity type; a photoelectric conversion layer of the first conductivity type in contact with the upper layer of the depletion-layer extension-promotion region , having a lower impurity concentration than the upper layer; a surface-buried region of a second conductivity type buried in a part of an upper portion of the photoelectric conversion layer , configured to implement a photodiode together with the photoelectric conversion layer ; a well region of the first conductivity type buried in another part of the upper portion of the photoelectric conversion layer , having higher impurity concentration than the photoelectric conversion layer ; a charge-accumulation region of the second conductivity type buried in a part of an upper portion of the well region , configured to accumulate signal charges temporally; a plurality of intra-pixel circuit-elements merged in a part of the well region , configured to implement a circuit for reading out the signal charges from the charge-accumulation region ; and an injection-blocking element having a tab-region of the second conductivity type dividing the well region into no less than two at least at a part of the well region , configured to block injection of non-signal charges having opposite conductivity type to the signal charges from the well region into the photoelectric conversion layer by a potential profile generated by a junction between the tab-region of the second conductivity type and the well region of the first conductivity type, wherein an entire range intended as a signal-charge generation-region in the photoelectric conversion layer is depleted by a voltage applied to the upper layer, with aid of the relative impurity concentrations of the photoelectric conversion layer and the upper layer . <EOS>