A CCD color image sensor which prevents unnecessary charge from overflowing in a photoelectric conversion element. An image input apparatus having the CCD color image sensor comprises transferring unit which transfers effective charge accumulated in the photoelectric conversion element provided for each of the colors (R, G and B), extracted as an output signal, to a shift register by opening a shift gate; and discarding unit which discards unnecessary charge accumulated in the photoelectric conversion element by opening the shift gate at different timing from one color to another immediately before the photoelectric conversion element starts accumulating effective charge again. The discarding unit discards unnecessary charge immediately before effective charge accumulates, and discards unnecessary charge by opening the shift gate before unnecessary charge overflows in the photoelectric conversion element.