PURPOSE: To form a photoelectric surface wherein the S/N ratio of emitted electrons for incident light is improved without lowering the electron emission efficiency in the effective region and cross talks between channels is decreased and to provide a photoelectric conversion tube using the photoelectric surface.

CONSTITUTION: A photoelectric surface includes a photoelectric surface portion 2 formed of a group 3-5 compound semiconductor and an oxide layer 7 formed around the photoelectric region. Optically, the photoelectric surface portion 2 of a group 3-5 compound semiconductor is of a galliumarsenic compound semiconductor and the oxide layer contains aluminum with its surface being oxidezed. In the photoelectric surface of the group 3-5 group compound semiconductor the electron emission efficiency is high. An oxide layer 7 is formed around the photoelectric region. Electron emission from the oxide layer 7 is conciderably decreased and the S/N ratio is improved. Also emission of photoelectrons due to the incident light is suppressed and the cross talk is decreased.