PURPOSE: To enable the control and reproducibility of an electron beam effect by forming slit patterns which regulate the current conductor from a releasing means between at least two tap regions of the releasing means in order to impress currents for the purpose of heating the releasing means.

CONSTITUTION: This cathode structural body apparatus is provided with the electrically conductive releasing means for regulating the releasing surface and the heating structural body. The heating structural body comprises the releasing means for regulating the releasing surface 3. The releasing means, therefore, have the slit 7a, 7b patterns. The slit 7a, 7b patterns regulate the current conductor from the releasing means between at least two pieces of the tap regions 9a, 9b of the releasing means for impressing the currents via the releasing means for heating the releasing means by Joule heat. As a result, the selective control of local electron emissivity is made possible.