An image display apparatus includes scanning line control circuits for supplying a scanning voltage V.sub.scan for selecting a plurality of electron sources in a unit of line to scan them in the vertical direction to the selected electron sources, a signal line control circuit for supplying a drive voltage V.sub.data based on an image signal to the electron sources of one line, and a signal processing circuit having a correction circuit, and the correction circuit corrects the image signal to add to the drive voltage V.sub.data an offset for compensating a voltage drop caused by an internal resistance R of a switch circuit in the scanning line control circuit, so that the voltage drop caused by the internal resistance of the switch circuit is compensated to lower or suppress reduction of brightness.