[en] The purpose of the present work is to study the composition of the emitted ions and to characterize the surface composition of MCP as function of temperature using ESD, AES and SEM techniques. It is found, that sodium and potassium have significant contribution to the desorbed ions. Intensity of these elements increased with increasing surface temperature. The presence of water and hydroxyl ions was negligible. Heating of the surface simultaneously with electron bombardment resulted in changes of the chemistry of the surface, which consisted mainly in a decrease of C and in an increase of Na and K on the surface