A color signal correcting method for correcting a color signal of each pixel outputted from a single-plate color image pickup element having a given color filter arrangement to correct a color reproduction error in an image, comprising the steps of: computing color signals of filter colors other than a filter color at the spatial location of a pixel to be corrected, wherein the other color signals at the spatial location are computed on the basis of color signals of a plurality of pixels of the same filter color located around the pixel to be corrected; and obtaining a correction value by multiplying the color signal of the pixel to be corrected and the computed other color signals by a predetermined correction coefficient and combining the products.