PURPOSE: To realize the landing quantity automatic measurement device measuring automatically the landing state of an electronic beam quantitatively only with a simple device in the measurement device for the landing of the electron beam of a color display device using a cathode ray tube.

CONSTITUTION: A sensor section 3 is arranged to a screen face 2 of a cathode ray tube and a controller 5 connected to a computer 6 measures automatically the electron beam landing state of the screen face 2. The sensor section 3 is provided with a coil 10 deflecting the electron beam locally in parallel with the screen face 2, a brightness sensor 12 measuring the brightness of the screen of the part subject to deflection.