A vacuum evaporator is characterized in that hot-cathode filaments (7) are provided as the electron source around a tip of a rod evaporation material (4); the peripheries of the rod evaporation material (4) and the hot-cathode filaments (7) are disposed in parallel to a conductive cooling member (1) of a good heat conductive metal which is partly contacted with the atmosphere to decrease the dissipation of radiation heat produced from the hot-cathode filaments (7) and a tip (41) of the rod evaporation material (4) into a vacuum vessel a; heat absorbed by the conductive cooling member (1) is quickly conducted through the conductive cooling member and discharged to the atmosphere to prevent the temperature of the electron impact heating part from increasing and to prevent the increase of the gas discharge due to the heat dissipation from the electron impact heating part.