A charge-modulation element comprising: a pixel constructing area (32, 34, 35) including: an active-area setting-layer of a first conductivity type, a surface buried region of a second conductivity type provided in an upper portion of the active-area setting-layer, and a pinning layer of the first conductivity type being in contact with a surface of the surface buried region, wherein the surface buried region is positioned between the active-area setting-layer and the pinning layer; an insulating film provided on the pixel constructing area (32, 34, 35); a light-receiving area assigned at a central portion of the pixel constructing area (32, 34, 35); first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) of the second conductivity type, having a higher impurity concentration than the active-area setting-layer; and first, second, third, and fourth field-control electrode pairs (41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b) being provided at positions surrounding the light-receiving area as pairs to both sides of respective charge transport paths, characterized in that the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) are allocated at quadruple positions with an orthogonal mirror symmetry with respect to the center position of the light receiving area, the orthogonal mirror symmetry having two axes of symmetry, the two axes being mutually perpendicular, and the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) are separated from each other at the quadruple positions symmetric with respect to the center position of the light-receiving area, surrounding the light-receiving area, and in that four directionally branched charge transport paths extend from the center position of the light-receiving area in the surface buried region to the respective first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64), wherein the charge-modulation element further comprises means configured to sequentially change depletion potentials of the surface buried region, by periodically applying field-control pulses at different phases to the first, second, third, and fourth field-control electrode pairs (41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b), and thus, for generating a potential gradient for transporting the charges in one of the charge transport paths, so that the destination of majority carriers generated in the surface buried region is controlled so as to be sequentially set to one of the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64). a pixel constructing area (32, 34, 35) including: an active-area setting-layer of a first conductivity type, a surface buried region of a second conductivity type provided in an upper portion of the active-area setting-layer, and a pinning layer of the first conductivity type being in contact with a surface of the surface buried region, wherein the surface buried region is positioned between the active-area setting-layer and the pinning layer; an active-area setting-layer of a first conductivity type, a surface buried region of a second conductivity type provided in an upper portion of the active-area setting-layer, and a pinning layer of the first conductivity type being in contact with a surface of the surface buried region, wherein the surface buried region is positioned between the active-area setting-layer and the pinning layer; an insulating film provided on the pixel constructing area (32, 34, 35); a light-receiving area assigned at a central portion of the pixel constructing area (32, 34, 35); first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) of the second conductivity type, having a higher impurity concentration than the active-area setting-layer; and first, second, third, and fourth field-control electrode pairs (41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b) being provided at positions surrounding the light-receiving area as pairs to both sides of respective charge transport paths, characterized in that the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) are allocated at quadruple positions with an orthogonal mirror symmetry with respect to the center position of the light receiving area, the orthogonal mirror symmetry having two axes of symmetry, the two axes being mutually perpendicular, and the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64) are separated from each other at the quadruple positions symmetric with respect to the center position of the light-receiving area, surrounding the light-receiving area, and in that four directionally branched charge transport paths extend from the center position of the light-receiving area in the surface buried region to the respective first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64), wherein the charge-modulation element further comprises means configured to sequentially change depletion potentials of the surface buried region, by periodically applying field-control pulses at different phases to the first, second, third, and fourth field-control electrode pairs (41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b), and thus, for generating a potential gradient for transporting the charges in one of the charge transport paths, so that the destination of majority carriers generated in the surface buried region is controlled so as to be sequentially set to one of the first, second, third, and fourth charge-accumulation regions (61, 62, 63, 64).