An image sensor comprising: a pixel array including a column on which a plurality of first photoelectric conversion units for converting light of a first color into charges and a plurality of second photoelectric conversion units for converting light of a second color into charges are arranged alternately in a column direction; a plurality of first charge-voltage converters, each for converting charges generated by a pixel unit comprising 2N + 1 (N is a positive integer) first photoelectric conversion units successive in the column direction into a voltage; a plurality of second charge-voltage converters, each for converting charges generated by 2N + 1 (N is a positive integer) second photoelectric conversion units successive in the column direction into a voltage; a first output line (VL1-1) arranged in the column direction and to which a first signal corresponding to the voltage of the first charge-voltage converter is output; a second output line (VL1-2) arranged in the column direction and to which a second signal corresponding to the voltage of the second charge-voltage converter is output; further comprising a driving unit configured to drive the pixel array to parallel-perform: a first operation to transfer charges of 2M or 2M+1 (M being a positive integer equal to or smaller than N) of the first photelectric conversion units to the first charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the first charge-voltage converter and to output the first signal corresponding to the voltage converted by the first charge-voltage converter to the first vertical output line; and a second operation to transfer charges of 2M or 2M+1 of the second photelectric conversion units to the second charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the second charge-voltage converter and to output the second signal corresponding to the voltage converted by the second charge-voltage converter to the second vertical output line. a pixel array including a column on which a plurality of first photoelectric conversion units for converting light of a first color into charges and a plurality of second photoelectric conversion units for converting light of a second color into charges are arranged alternately in a column direction; a plurality of first charge-voltage converters, each for converting charges generated by a pixel unit comprising 2N + 1 (N is a positive integer) first photoelectric conversion units successive in the column direction into a voltage; a plurality of second charge-voltage converters, each for converting charges generated by 2N + 1 (N is a positive integer) second photoelectric conversion units successive in the column direction into a voltage; a first output line (VL1-1) arranged in the column direction and to which a first signal corresponding to the voltage of the first charge-voltage converter is output; a second output line (VL1-2) arranged in the column direction and to which a second signal corresponding to the voltage of the second charge-voltage converter is output; further comprising a driving unit configured to drive the pixel array to parallel-perform: a first operation to transfer charges of 2M or 2M+1 (M being a positive integer equal to or smaller than N) of the first photelectric conversion units to the first charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the first charge-voltage converter and to output the first signal corresponding to the voltage converted by the first charge-voltage converter to the first vertical output line; and a second operation to transfer charges of 2M or 2M+1 of the second photelectric conversion units to the second charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the second charge-voltage converter and to output the second signal corresponding to the voltage converted by the second charge-voltage converter to the second vertical output line. a first operation to transfer charges of 2M or 2M+1 (M being a positive integer equal to or smaller than N) of the first photelectric conversion units to the first charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the first charge-voltage converter and to output the first signal corresponding to the voltage converted by the first charge-voltage converter to the first vertical output line; and a second operation to transfer charges of 2M or 2M+1 of the second photelectric conversion units to the second charge-voltage converter to add the transferred charges, to convert the added charges into a voltage by the second charge-voltage converter and to output the second signal corresponding to the voltage converted by the second charge-voltage converter to the second vertical output line.