Thin film cold cathodes composed of a graphite-type carbon coating on Si substrate have been fabricated and tested. Electrons from the cathodes were emitted into vacuum when the average electric field exceeded 1.5 V/mu m. The emission current density was more than 1 mA/cm(2) and emission site density was higher than 10(7) cm(-2) at the electric field of 4 V/mu m. The current-voltage dependencies were studied at different temperatures from 77 to 600 K and found to be typical for the field emission. We propose a mechanism of electron,emission from carbon cold cathodes, based on the enhancement of electric field due to surface morphology and on the modification of electronic properties of carbon atoms localized on the surface of graphite-type material.