Abstract: A convergence measurement apparatus for a color cathode-ray tube is capable of high precision convergence measurement by elimination of luminance omission portions occurring in the screen. A dot pattern displayed on a color cathode-ray tube is picked up by an image pickup camera and is stored in an image memory. A signal movement amount control unit is arranged to move a beam spot of the dot pattern displayed on the cathode-ray tube by a predetermined pitch in a horizontal or vertical direction. Corresponding dot pattern shifting occurs to sequentially record images of discrete colors for a more accurate measure of convergence. For example, if a gap between adjacent phosphor elements of one color (for example red) is defined as one pitch, three sequential red dot patterns can be each shifted by 1/3 of a pitch and thereafter picked up and stored in the image memory of dot pattern data.