PURPOSE: To provide an auxiliary device for correcting die casting dies which eliminates the need for carrying the dies and enables inexpensive and short-time manufacture of the dies by providing a mechanism for forcing a molten metal into the cavity formed between both dies when a set of the dies are closed.

CONSTITUTION: A piston rod 20 of a die clamping cylinder 19 is retracted and a lifting base 18, a supporting plate 21 and the other die 24 are moved upward to open both dies 12, 24 in the stage of correcting the dies. A moving base 9 and one die 12 are then linearly moved forward along a track 8 and are pushed out to the outside from the space enclosed by tie rods 5. A rod mechanism 31 is removed in this stage; at the same time, the piston rod 27 of an oscillating cylinder 26 is projected and the plate 21 and die 24 are oscillated around one end until both are positioned approximately perpendicular. Both dies 12, 24 are corrected in this state and a test is carried out. The die 12 and the base 9 are thereafter moved to right below the die 24, and a molten metal is injected into a sleeve 41, then the sleeve 41, the base 9 and the die 12 are heated to the end of the test to prevent the solidification of the molten metal. Both dies 12, 24 are closed by the downward movement of the base 18 to form a cavity during die clamping.