An image storage tube is provided, which comprises a transparent back plate coated on one face with a storage layer made of a cathodochromic material and on the other with an electrically resistive coating; an electron gun including a cathode adapted to be maintained substantially at the earth potential and spaced from the back plate; and a apparatus for erasing an image stored in the storage layer which includes an image erasing power source for supplying a current to the resistive coating, a switch means for connecting the erasing power source with the back plate when energized, a high voltage generator for applying to the back plate a high voltage relative to the cathode, and control means for alternatively energizing the switch means and the high voltage generator.