To provide a method and an apparatus for producing a magnesium alloy ingot excellent in the quality containing the surface which can be obtained without developing the difficulty on the mechanism.

The apparatus produces the magnesium alloy ingot, so that the ingot can be obtained by pouring molten magnesium alloy into a mold from a molten metal pouring hole in a molten metal pouring nozzle and solidifying. This apparatus is provided with; a double structural cover case, in which a space exits between both of an outer cylinder and an inner cylinder, and both cylinders are connected through a ring piece at the upper part; a heat-insulating cylinder arranged in the inner peripheral part of the inner cylinder; the molten metal pouring nozzle penetratingly inserted in the axial direction of the inner cylinder at the inside of the heat-insulating cylinder; a heater wound on the outer peripheral part of the molten metal pouring nozzle; the mold arranged at the lower part of this cover case and this molten metal pouring nozzle; a sealing material arranged on the ring-shaped cover body of the mold faced to the outer cylinder of the cover case; and an ascending/descending device for cover case. The outer cylinder of the cover case is integrally ascended/descended with the molten metal pouring nozzle under state of slidingly moving to the seal material arranged on the cover body of the mold by operating the ascending/descending device.