PURPOSE: To provide a metal vapor laser capable of feeding a metal in a short time requiring almost no human labor.

CONSTITUTION: A metal vapor laser is formed in a structure, wherein a metal for producing metal vapor, which is a laser oscillation medium, is fed in a discharge tube is put in a vacuum state, and the metal in this discharge tube is discharged and heated to generate a laser beam. The laser is provided with a reservoir heater 27 for melting by heating the metal outside of the tube 1, a reservoir tank 26 for storing the molten metal 8 and feeding means 29 and 30 for feeding the stored molten metal 8 to a prescribed position in the tank 1 without reducing the degree of vacuum in the tube 1.