A solid state imaging apparatus includes a plurality of pixels two-dimensionally arranged in the row direction and the column direction, and every two of the plurality of pixels that are adjacent to each other in the row direction or the column direction include color filters of different colors, respectively. A signal mixture circuit is provided in each same-row and same-color pixel group. Each said same-row and same-color pixel group consisting of ones of the plurality of pixels which are included in a pixel mixture unit to be a subject of pixel signal mixture, which are located in the same row, and which include color filters of the same color. The signal mixture circuit includes a combination of a capacitor and a transmission switch, stores pixel signals from pixels included in a same-row and same-color pixel group and mixes the signals together.