A solid-state imaging device comprising: a plurality of photoelectric conversion units (11, 111-118) a floating diffusion unit that is shared by the plurality of photoelectric conversion units and configured to convert electric charge generated in each of the plurality of photoelectric conversion units into a voltage signal; a plurality of transfer units that are respectively provided in the plurality of photoelectric conversion units and configured to transfer the electric charge generated in the plurality of photoelectric conversion units to the floating diffusion unit; a first transistor group (31, 61) that is electrically connected to the floating diffusion unit and includes a gate and source/drain which are arranged with a first layout configuration; a second transistor group (32, 34, 35, 36, 62) that is electrically connected to the floating diffusion unit, includes a gate and source/drain arranged with a second layout configuration symmetrical to the first layout configuration with respect to a straight line passing the center between both the transistor groups and extending in a direction intersecting at right angles to an arrangement direction between both the transistor groups within the plane in which the first transistor group and the second transistor group are formed such that the layout pattern and/or the area of the respective gate and the source / drain of the first and second transistor groups is the same between the first transistor group and the second transistor group, and is provided in a separate area from the first transistor group; and characterized in that the solid-state imaging device further comprises a well contact (23a, 23b) electrically connecting a well area in which the plurality of photoelectric conversion units, the floating diffusion unit, the transfer units, the first transistor group and the second transistor group are formed, wherein the well contact is formed in an area different from the formation areas of the first transistor group and the second transistor group in a surrounding area of a formation area of the plurality of photoelectric conversion units and is formed at a position where the arrangement direction from the first transistor group to the second transistor group is perpendicular to a direction from the well contact to the floating diffusion unit. a plurality of photoelectric conversion units (11, 111-118) a floating diffusion unit that is shared by the plurality of photoelectric conversion units and configured to convert electric charge generated in each of the plurality of photoelectric conversion units into a voltage signal; a plurality of transfer units that are respectively provided in the plurality of photoelectric conversion units and configured to transfer the electric charge generated in the plurality of photoelectric conversion units to the floating diffusion unit; a first transistor group (31, 61) that is electrically connected to the floating diffusion unit and includes a gate and source/drain which are arranged with a first layout configuration; a second transistor group (32, 34, 35, 36, 62) that is electrically connected to the floating diffusion unit, includes a gate and source/drain arranged with a second layout configuration symmetrical to the first layout configuration with respect to a straight line passing the center between both the transistor groups and extending in a direction intersecting at right angles to an arrangement direction between both the transistor groups within the plane in which the first transistor group and the second transistor group are formed such that the layout pattern and/or the area of the respective gate and the source / drain of the first and second transistor groups is the same between the first transistor group and the second transistor group, and is provided in a separate area from the first transistor group; and characterized in that the solid-state imaging device further comprises a well contact (23a, 23b) electrically connecting a well area in which the plurality of photoelectric conversion units, the floating diffusion unit, the transfer units, the first transistor group and the second transistor group are formed, wherein the well contact is formed in an area different from the formation areas of the first transistor group and the second transistor group in a surrounding area of a formation area of the plurality of photoelectric conversion units and is formed at a position where the arrangement direction from the first transistor group to the second transistor group is perpendicular to a direction from the well contact to the floating diffusion unit.