PURPOSE: To stably coat a dielectric film by providing a metallic sheet at a specified distance from the edge of an arc discharge cathode in the horizontal direction to enclose the whole periphery of a target.

CONSTITUTION: The vacuum-arc vapor deposition device is basically constituted of a vacuum vessel 1 consisting or three vacuum chambers 2, 3 and 4 and integrally grounded. An arc discharge cathode 10 is provided at the bottom of the chamber 3 through an electrical insulator 9. A water-cooled metallic sheet 19 is vertically furnished at the distance of 20-200mm from the edge of the cathode 10 in the horizontal direction to enclose the cathode 10. The distance between the upper end of the sheet 19 and the surface of a target 20 is controlled to 50-200mm. The sheet 19 functions as an arc discharge anode. Consequently, a dielectric thin film is continuously deposited on a substrate for a long time by vacuum-arc vapor deposition.