To provide a metal melting furnace for melting a metal material to manufacture a molten metal efficiently, and a metal melting method.

The metal melting furnace 1 manufactures a molten metal 20 by melting a metal material 14 containing aluminum, and includes a melting chamber 2 in which the metal material 14 is melted into the molten metal 20 by a heating means 4, and a hot water supply chamber 3 which communicates with the melting chamber 2 and has a hot water supply port 6. The melting chamber 2 includes the heating means 4, and a furnace internal pressure control means 5 which controls an internal pressure of the melting chamber 2 at a position higher than the hot water supply port 6. The molten metal 20 is oscillated by varying the internal pressure of the furnace in the melting chamber 2 through the furnace internal pressure control means 5. A metal melting method includes: a melting step of obtaining the molten metal 20 by mounting the metal material 14 containing aluminum in the melting chamber 2 and melting the metal material 14 using the metal melting furnace 1; and an agitating step of oscillating the molten metal 20 while varying the internal pressure of the furnace in the melting chamber 2.